Airborne particle monitor

ABSTRACT

An airborne particle collection system includes a monitoring device and a collection media. The monitoring device includes a housing having an air-intake slot, and a motor. The collection media includes an adhesive-coated tape contained within a removable cartridge inserted into the housing. The removable cartridge includes a particle intake zone, proximate to the air-intake slot, and through which the adhesive-coated tape is exposed to capture airborne particles passing through the air-intake slot, and an inspection zone at which the airborne particles captured at the intake zone are transported for optical imaging. The motor moves the airborne particles captured by the adhesive-coated tape from the particle intake zone to the inspection zone.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/061,883, filed Mar. 4, 2016, and of InternationalApplication PCT/US2016/021058, with an international filing date of Mar.4, 2016, which claim priority to U.S. provisional patent applications62/129,571 filed Mar. 6, 2015, and 62/188,606, filed Jul. 3, 2015 andclaims the benefit of U.S. provisional patent applications 62/173,280,filed Jun. 9, 2015; and 62/210,253, filed Aug. 26, 2015. Theseapplications along with other cited references in this application areincorporated by reference.

BACKGROUND

Monitoring air quality is of great importance in protecting againstadverse health effects and also damage to farm crops such as vineyards.Indeed, there is an unmet need to provide individuals with personalizedand actionable information regarding their exposure to allergens. Pollenexposure information may be considered actionable if it aids a user andassociated health care providers in diagnosing the type of allergensinducing allergic reactions. Allergen exposure information is alsoactionable if it enables the user to better avoid allergen exposure.Information is also actionable information if it leads to more effectiveuse of medication or therapy to reduce or eliminate allergic reactionsand associated symptoms. One particularly important mechanism forallergen exposure is the inhalation of airborne allergens. Henceactionable information regarding airborne allergen exposure is ofparticular interest.

Airborne allergens include tree, grass and weed pollens, mold spores,cat or dog dander, as well as particulates associated with dust mites.Troublesome airborne allergens typically are sufficiently small to beeasily transported some distance by air currents or wind before settlingout of the air. Typically this means small particle sizes that aredifficult to see with the naked eye. Airborne allergens are typically aninvisible threat to an individuals' well-being.

Similarly, farms and vineyards can suffer from certain types of mold aswinds can carry mold spores for many miles. Depending on climaticconditions, losses for vineyards may range from about 15 percent toabout 40 percent or more of the harvest. The lost in harvest results inlost revenue, profit, and jobs. There is a need to cost-effectively andrapidly detect damaging mold spores so that control and mitigationmeasures can be quickly developed and deployed to save a harvest.Likewise, there remains an unmet need to provide individuals withpersonalized, prompt and actionable information regarding their exposureto allergens.

BRIEF SUMMARY OF THE INVENTION

An airborne biological particle monitoring device collects particlesfloating in air. The monitor includes a camera sensor, illuminationsource, and quantum-dot illumination source. The camera sensor capturesat least a first image of the particles when the collected particles areilluminated by the illumination source. The camera sensor captures atleast a second image of the particles when the collected particles areilluminated by the quantum-dot illumination source. The at least firstand second images are analyzed to identify the collected particles.

The camera sensor may include a red-green-blue (RGB) camera sensor. Inan embodiment, the quantum-dot illumination source includes a lightemitting element; and a film, including quantum dots, and positioned toreceive first light from the light emitting element and convert thefirst light into second light, where the second light illuminates thecollected particles for the second image.

The light emitting element may include a light emitting diode (LED). Thequantum-dot illumination source may include a light emitting diode (LED)having quantum dots.

In an embodiment, the quantum-dot illumination source includes a lightemitting diode (LED); and a collection media that traps the particles,where the collection media comprises quantum dots, and is positioned toreceive first light from the LED and convert the first light into secondlight, and where the second light illuminates the particles trapped bythe collection media for the second image.

The collection media may include tape including a layer of adhesive, anda backing material upon which the layer of adhesive is placed, and wherethe quantum dots are within the layer of adhesive. The collection mediamay include tape including a layer of adhesive, and a backing materialupon which the layer of adhesive is placed, and where the quantum dotsare within the backing material.

In an embodiment, the quantum-dot illumination source includes anarrower emission spectra than the illumination source, the narroweremission spectra having a spectral peak with full-width-half-maximumless than 50 nanometers. In another specific embodiment, the narroweremission spectra comprises a spectral peak with full-width-half-maximumless than 25 nanometers. The full-width-half-maximum spectral width maybe about 50, 40, 30, 25 nanometers, or less than 25 nanometers.

At least one of the illumination source or the quantum-dot illuminationsource may illuminate the collected particles with infrared light. Atleast one of the illumination source or the quantum-dot illuminatesource may illuminate the collected particles with ultraviolet light.The illumination source may include a light emitting diode (LED) and theemitted first light by the LED may be white light.

The quantum-dot illumination source may include a light emitting diode(LED) emitting blue light, and a film including quantum-dots thatreceives the blue light, where the film converts the blue light into anarrow spectrum centered an absorption peak of chlorophyll-a as may beachieved via use of quantum dots that emit light at approximately 665nanometers. The quantum-dot illumination source may include a lightemitting diode (LED) emitting blue light, and a film comprisingquantum-dots that receives the blue light, wherein the film converts theblue light into a narrow spectrum centered on an absorption peak ofchlorophyll-a.

In an embodiment, the processor is adapted to identify a collectedparticle as being of a particular type of pollen by transmitting to aremote server a geographical location of the monitor, and obtaining fromthe remote server context information based on the geographical locationof the monitor. The context information may include at least one ofpollen types known to be currently blooming at the geographicallocation, wind patterns at the geographical location, or a listing ofpollen types detected by other monitors.

The monitor may further include a battery, connected to and supplyingpower to the processor, camera sensor, illumination source, andquantum-dot illumination source. The monitor may further include asensor, connected to the processor, to determine a current location ofthe pollen monitoring device; and a network interface controller,coupled to the processor, to receive over a network context informationassociated with the current location. The monitor may include a storagedevice storing a plurality of images of different types of particles, orparameters for algorithms that discriminate between different types ofparticles, or both. The quantum-dot illumination source may includesize-tuned quantum dots, composition-tuned quantum dots, or both.

In an embodiment, there is a removable collection cartridge thatincludes a tape upon which the particles are trapped, and a tape guidethat supports the tape, where at least a portion of the tape guideincludes quantum-dots, the at least a portion of the tape guide therebybeing the quantum-dot illumination source.

In another specific embodiment, a method for identifying airbornebiological particles includes collecting the particles onto a collectionmedia, illuminating the collected particles with first light, capturinga first image of the collected particles illuminated with the firstlight, illuminating the collected particles with second light, differentfrom the first light, where the second light comprises light emittedfrom quantum dots, capturing a second image of the collected particlesilluminated with the second light, and analyzing the first and secondimages to identify the collected particles.

In another specific embodiment, a method for identifying airbornebiological particles includes collecting, by a particle monitor, theparticles onto a collection media, illuminating, by the particlemonitor, the collected particles with first light, capturing, by theparticle monitor, a first image of the collected particles illuminatedwith the first light, illuminating, by the particle monitor, thecollected particles with second light, different from the first light,where the second light comprises light emitted from quantum dots,capturing, by the particle monitor, a second image of the collectedparticles illuminated with the second light, analyzing, by the particlemonitor, the first and second images to identify the collectedparticles, determining, by the particle monitor, that the particlescannot be satisfactorily identified from the analysis of the first andsecond image, and in response to the determination, issuing, by theparticle monitor, a request to a server for context informationassociated with a geographical location of the particle monitor.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a block diagram of an airborne particle monitoring systemaccording to an embodiment.

FIG. 2 shows another block diagram of an airborne particle monitoringsystem according to an embodiment.

FIG. 3 shows an allergic reaction timing diagram.

FIG. 4 shows a block diagram of an airborne particle monitor accordingto one embodiment.

FIG. 5 shows a block diagram of an airborne particle monitor accordingto another embodiment.

FIG. 6 shows a block diagram of a cloud server according to anembodiment.

FIG. 7 shows a block diagram of a mobile device according to anembodiment.

FIG. 8 shows an overall flow of a process for detecting and identifyingairborne allergens according to an embodiment.

FIG. 9 shows a block diagram of an airborne particle monitor accordingto another embodiment.

FIG. 10 shows an exterior view of an airborne particle monitor accordingto a specific embodiment.

FIG. 11 shows an isometric view of a particle media cartridge that maybe used with the particle monitor shown in FIG. 10.

FIG. 12 shows a plan view of a cross section of the cartridge shown inFIG. 11.

FIG. 13 shows a plan view of a cross section of the particle mediacartridge including media of the cartridge shown in FIG. 11.

FIG. 14 shows a plan-view of the particle monitor shown in FIG. 10including motors.

FIG. 15 shows a vertical cross-section of the particle monitor shown inFIG. 10 illustrating the placement of electronic boards.

FIG. 16 shows some detail of the particle monitor shown in FIG. 10 withoptics and particle media cartridge, as well as illustration of airflow.

FIG. 17 shows a side view of an inside portion of the particle monitorshown in FIG. 10.

FIG. 18 shows an enlarged side-view cross-section of the particlemonitor shown in FIG. 10 showing further details of the optical andillumination system according to a specific embodiment.

FIG. 19 is a graph showing spectral characteristics typical of an RGBcamera sensor.

FIG. 20 shows the expansion of band-gap of energy levels for smallquantum dots due to the quantum confinement effect.

FIG. 21 is a graph showing a quantum-dot emission spectrum.

FIG. 22 is a graph showing the absorption spectrum of chlorophyll-a.

FIG. 23 shows a quantum-dot containing film wavelength shifting lightfrom a conventional LED.

FIG. 24 shows a quantum-dot containing LED directly generating light ofa desired wavelength.

FIG. 25 shows an enlarged side-view cross-section of a particle monitorhaving a quantum-dot LED according to another specific embodiment.

FIG. 26 shows an enlarged side-view cross-section of a particle monitorhaving a quantum-dot adhesive tape according to another specificembodiment.

FIG. 27 shows a top view of an inspection platform of a particle monitoraccording to another specific embodiment.

FIG. 28 shows a plot combining camera-sensor sub-pixel spectralcharacteristics as shown in FIG. 19 with illumination source spectralcharacteristics.

FIG. 29 shows an example of an achromatic lens and its operation.

FIG. 30 shows a “liquid lens” in a first state that may be included in aparticle monitor in another specific embodiment.

FIG. 31 shows the “liquid lens” from FIG. 30 in a second state.

FIG. 32A shows a top view of a disk having various separate regions ofdifferently sized quantum dots.

FIG. 32B shows a cross section of a film having a mixture of differentlysized quantum dots.

FIG. 32C shows a cross section of a stack of films, each film having aset of quantum dots of a size that differ in size from another film ofthe stack.

FIG. 33 shows an overall flow illustrating some basic ingredients ofautomated particle (e.g., pollen) monitoring according to a specificembodiment.

FIG. 34 shows an overall flow of a process for identifying ordiscriminating particles according to another specific embodiment.

FIG. 35 shows a first image of particles captured under first lightingconditions.

FIG. 36 shows a second image of particles captured under second lightingconditions.

FIG. 37 shows a block diagram of a particle information packet accordingto an embodiment.

FIG. 38 shows a block diagram of history for the particle informationpacket according to an embodiment.

FIG. 39A shows a flow of a process for associating an image of thecollected particles with their corresponding location on the adhesivecoated tape according to an embodiment.

FIG. 39B shows a flow of a process for server-aided particleidentification or discrimination.

FIG. 40 shows a side view of a particle monitor according to anotherspecific embodiment.

FIG. 41 shows another side view of the particle monitor shown in FIG.40.

FIG. 42 shows a top cross-section view of the particle monitor shown inFIG. 40.

FIG. 43 shows another top cross-section view of the particle monitorshown in FIG. 40.

FIG. 44 shows a side view of a particle monitor according to anotherspecific embodiment.

FIG. 45 shows another side view of the particle monitor shown in FIG.44.

FIG. 46 shows a top cross-section view of the particle monitor shown inFIG. 44.

FIG. 47 shows another top cross-section view of the particle monitorshown in FIG. 44.

FIG. 48 shows a top view of a particle monitor that does not include acamera sensor according to another specific embodiment.

FIG. 49 shows a front view of the particle monitor shown in FIG. 48.

FIG. 50 shows a side view of a particle monitor according to anotherspecific embodiment.

FIG. 51 shows a block diagram of a wearable computer having a particleidentification app installed.

FIG. 52 shows an example of a kit including particle collectioncartridges.

FIG. 53 shows a block diagram of a client-server system and network inwhich an embodiment of the system may be implemented.

FIG. 54 shows a system block diagram of a client or server computersystem shown in FIG. 53.

DETAILED DESCRIPTION

FIG. 1 is a block diagram of an airborne particle collection, detectionand recognition system 100 according to a specific embodiment. Such asystem may address unmet needs of individuals or “users” or “consumers”for personalized and actionable information regarding their exposure toairborne particles such as pollen, mold, or other airborne particles. Ina specific embodiment, airborne allergens of interest include tree,grass and weed pollens, mold spores, cat or dog dander, as well asparticulates associated with dust mites. Botanically, “pollen” isessentially the plant version of sperm that serves to fertilize an egg,but by itself cannot grow into a plant. In contrast, a spore isself-contained in the sense that it has everything it needs to grow intomold or a plant. Monitoring of airborne allergenic particles is ofparticular interest to a large number of individuals as many peoplesuffer from pollen allergies.

An airborne particle monitoring system as illustrated in FIG. 1 may alsoaddress needs related to monitoring of airborne agricultural pathogensas well as monitoring of air quality.

In the example shown in FIG. 1, the system includes a personal airborneparticle monitoring device 105 and a remote cloud server 110 that isconnected to the monitoring device via a communication network 115. Theparticle monitoring device may be referred to as a particle detector,pollen detector, particle collector, pollen monitor, pollen collectionmachine, or airborne biological particle monitoring device.

The monitoring device is a relatively small device or appliance that isdesigned to be placed in a local environment 120 of a user 125. Forexample, in a specific embodiment, the monitoring device is containedwithin a cylindrical housing having a diameter of about 100 millimeters(mm) and a height of about 150 mm. The relatively small size of themonitoring device allows the device to be placed unobtrusively in theuser's home or office without occupying much space. The monitoringdevice may be deployed in an indoor environment or an outdoorenvironment (e.g., user's backyard).

The user may be a person who suffers from allergies. The system shown inFIG. 1 can be used to help identify the specific types of airborneparticles that are responsible for the user's allergic reaction. Withthis information, a treatment plan can be developed to reduce oreliminate future allergenic reactions. In a specific embodiment, themonitoring device samples ambient air 130 and collects or traps airborneparticles that may be present or floating in the ambient air.

The monitoring device can use a combination of techniques to analyze,discriminate, and identify the collected particles. In a specificembodiment, the analysis includes capturing images (e.g., pictures,photographs, or snapshots) of the particles under various lightingconditions and examining the captured images. Particles, includingdifferent types of pollen, can be identified or discriminated based ontheir morphology (e.g., shape, surface texture, apertures, or size),color, or combinations of these as may be captured by a camera sensor ofthe particle monitor.

More particularly, particles such as a various types of pollen caninclude light-absorbing molecules or tissues. When light strikes aparticle some of the wavelengths may be absorbed while other wavelengthsare reflected. The reflected wavelengths contribute to the color of theparticle. For example, chlorophyll-a is generally found in plants.Chlorophyll-a absorbs blue and red light and reflects green light. Inother words, plants are green because blue and red light are absorbedwhile green light is reflected.

In some cases, a particle of interest may have a very narrow spectralrange in regards to what wavelengths are absorbed, what wavelengths arereflected, or both. Off-the-shelf components such as mass-producedlighting (e.g., light emitting diodes (LEDs)) and color camera sensorsused in consumer-grade cameras are relatively inexpensive but generallydo not provide the precision or sensitivity needed to accuratelyidentify or discriminate the vast array of airborne particles that maybe present in a user's local environment.

For example, a typical off-the-shelf red LED may emit wavelengthsranging from about 610 nanometers (nm) to about 760 nm. Differentmanufactures may each provide “red” LEDs, but the actual wavelengthsemitted may vary greatly between the general range of 610 nm to 760 nm.While this range is acceptable for many different consumer products suchas holiday lighting, vehicle dashboard displays, generic indicatorlights, and so forth, such a wide range is not sufficient fordiscriminating between different types of airborne particles.

Much more color information could be provided by scientific-gradespectroscopy equipment. However, a major drawback of spectroscopyequipment is that such precision equipment is often large, bulky, andvery expensive. Lasers, for example, are generally more expensive thanLEDs and it can be very expensive to specify and manufacture an LEDhaving a particular narrow emission spectra. Embodiments of thepresently described particle monitor provide improvements in airborneparticle identification or discrimination, and especially pollenidentification, over known devices and techniques. Systems andtechniques are provided for a particle monitor that is relativelyinexpensive yet can quickly and accurately identify or discriminatedifferent types of airborne particles. The faster airborne allergenexposure information is provided to the user, the more time the user hasto take actions based on the information.

In a specific embodiment, quantum dots are used in the particle monitorto provide a narrow emission spectra. Quantum dots, as described infurther detail below, are nanoscale particles of semiconducting materialthat can be embedded in various materials such as a polymer, plastic,glass, acrylic, silicone, adhesive, epoxy, or resin—just to name a fewexamples. A quantum dot can convert a wide range of incoming light intoa precise emission spectra. The color of light emitted by a quantum dotcan be precisely controlled based on the size of the quantum dot,composition, or both.

For example, bigger quantum dots (e.g., quantum dots with largediameters) emit longer wavelengths such as red, while smaller quantumdots (e.g., quantum dots with small diameters) emit shorter wavelengthssuch as green. The emission spectra emitted from the quantum dots can beprecisely configured or tuned to correspond to or match the absorptioncharacteristics of particles of interest (e.g., grass pollen, moldspores, and so forth).

As the emerging quantum-dot industry matures, it is anticipated that itwill be much less expensive to produce quantum dots as compared toproducing an LED (without quantum dots) having a particular narrowemission spectra. Quantum dots offer a level of control over theemission spectra that is very difficult and expensive to achieve withLEDs. In an embodiment, a particle monitor with quantum dots exploitsthe different absorption characteristics present in different particles.The collected particles are imaged, using an off-the-shelf color camerasensor, but under precise lighting conditions provided via the quantumdots and the collected particles are identified from the images.

In another specific embodiment, the analysis further includes combiningthe image analysis with context information that is obtained from theremote cloud server. The context information may include, for example,information regarding weather, wind conditions, humidity levels, thetypes of pollen currently blooming at the geographical location of thecollected particles, vegetation known to be present at the geographicallocation of the collected particles, other context information, orcombinations of these.

For example, in a specific embodiment, a particle monitoring devicegenerates a set of candidate particle identifications for a particularparticle that has been captured based on analyzing a set of images takenof the captured particle. After the set of candidate identificationshave been generated, the particle monitoring device issues a request tothe cloud server for context information. The request can include ageographical location of the particle monitoring device, time and dateof particle capture, or both. The cloud server receives the request anduses the geographical location of the monitoring device, time and dateof capture, or both to retrieve appropriate or relevant contextinformation to transmit to the monitoring device.

The monitoring device receives the appropriate context information andfurther analyzes the context information in conjunction with the set ofcandidate particle identifications. Consider, as an example, that one ofthe candidate identifications is ragweed. If, however, the contextinformation received by the particle monitor from the cloud serverindicates that ragweed is currently not blooming at the geographicallocation of the pollen monitor, the analysis can include a process ofelimination where ragweed is eliminated or excluded from the set ofcandidate particle identifications. This process of elimination cancontinue until a satisfactory identification has been made. Themonitoring device may include a display (e.g., electronic display) whichshows the type of airborne particle that has been identified.

The images of the particles captured by the monitoring device may betransmitted or sent to the remote cloud server for further analysis. Theanalysis may include a review of the images by a human technician. Forexample, in some cases, an image analysis and context informationanalysis may not lead to a satisfactory identification. In these cases,the analysis may be escalated to a human technician. In particular, theimages, associated metadata, or both can be transmitted to the cloudserver for review by a human technician. The associated metadata caninclude the geographical location of the particle monitor, time and dateof particle capture, or both.

In a specific embodiment, the particle monitoring device traps theairborne particles on a piece of media or medium that can be removed bythe user from the particle monitoring device. The media, with trappedairborne particles, may additionally be transported to a lab for anin-depth analysis. Consider, as an example, that the human technician isunable to identify with reasonable certainty the particle from theimages. The technician can escalate the analysis to an analysis of theactual collected particle. In particular, the technician can notify theuser that the collection media should be removed from the particlemonitoring device and delivered to a laboratory for an analysis of theactual collected physical particles. For example, the technician maytransmit through the system a notification to an app executing on theuser's mobile device. The app may display the message, “Please removeparticle collection media from your particle monitor and mail it to ourlaboratory for analysis.”

This technique of escalation may be referred to as tiered particleanalysis. Such an analysis helps to ensure judicious use of resourcesincluding computing resources (e.g., network bandwidth, storage) andhuman labor. Activities such as accessing a network, sending image filesover the network, human review, mailing the physical particles, and soforth consume resources. For example, an image file may be severalmegabytes in size. It can be desirable to refrain from transmitting theimage file over a network unless the transmission is deemed necessary.

In a specific embodiment, there is a first attempt to identify thecollected particles where the first attempt is performed locally (e.g.,at the particle monitor). If the first attempt fails to result in asatisfactory identification, a second attempt includes accessing aremote cloud server to obtain over a network context information. If thesecond attempt fails to result in the satisfactory identification, athird attempt includes transmitting over the network the image files tothe remote cloud server for human review. If the third attempt fails toresult in the satisfactory identification, a fourth attempt includesinstructing the user to mail the removable media with collectedparticles to a laboratory.

In a specific embodiment, the particle monitoring device is paired withone or more mobile devices 135 associated with or belonging to the user.The pairing allows the particle monitoring device and mobile device toexchange information, instructions, data, commands, or othercommunications. Mobile devices include, for example, smartphones, tabletcomputers, and wearable computers (e.g., Apple Watch, Google Glass). Themobile device may include sensors such as a microphone, camera,accelerometer, gyroscope, global positioning system (GPS) sensor, othersensors, or combinations of these.

A sensor can be used to detect user motions, actions, sounds, or otherphysiological events that may indicate the user is currently sufferingan allergic reaction (e.g., sneezing sound or coughing sound). Themobile device may include an allergic reaction detection applicationprogram or “app” that can determine from the signals generated from thesensors whether or not the user is suffering an allergic reaction. Adetermination that the user is suffering an allergic reaction can becommunicated to the particle monitoring device. The particle monitoringdevice receives and logs the allergic reaction so that the allergicreaction can be cross-referenced to particles collected by themonitoring device. The cross-referencing helps to determine theparticles that may be responsible for the user's allergic reaction. Themonitoring device may further transmit results of the particle analysis(e.g., an identification of a particle) to the mobile device for displayon the mobile device.

In another specific embodiment, the particle monitor itself may includean allergic reaction detection subsystem including one or more sensors(e.g., microphones) and logic in order to determine whether the usersuffered an allergic reaction. Detecting allergic reactions is furtherdescribed in U.S. patent application Ser. No. 15/061,883, filed Mar. 4,2016, which is incorporated by reference along with all other referencescited herein.

FIG. 2 is a block diagram showing some elements and processes of anairborne particle collection, detection, and recognition system 200according to a specific embodiment. Airborne particle monitoring system200 includes air intake hardware 220 to sample ambient air 210,particle-capture hardware 222 with which particles removed from ambientare collected and transported for microscopic analysis. The microscopesystem includes illumination hardware 224 that shines visible,ultraviolet (UV), or infrared (IR) light, or combinations of these oncaptured particles, and image-capture hardware 226 that may include alens assembly as well as a camera sensor. The light may include lightemitted from quantum dots. Capturing various images of the particleswhen illuminated under different conditions provides for additionaldimensions of analysis to help identify, classify, or discriminatebetween the collected particles.

Image processing software and hardware 228 processes image data from theimage-capture hardware 226. The types of the observed particles are thendecided by interpretation software 230. Finally, user-notificationsoftware 232 outputs the interpretation results in a form that can beunderstood by the user. For example, the output may include displayingon an electronic screen a message specifying the airborne particles thathave been collected and identified. The value of airborne particlemonitoring system 200 can be realized when it beneficially guides theuser to take an informed user action 280.

In some embodiments, particle-capture hardware 222 provides for a mediumthat can be removed with captured particles and archived for possiblefuture laboratory inspection, thus providing a physical archive 260 ofcaptured particles.

The actions and data processing of airborne particle monitoring system200 is orchestrated through a local processor 240. Local processor 240is preferably supported by other computing and data resources viadigital communication networks that may concisely be referred to as the“cloud”; see, e.g., cloud server of FIG. 1.

Local processor 240 and cloud 250 may support numerous feedback loops.Here is one example. Interpretation software 230 (which may be codeexecuted in a dedicated processor, or by the local processor, or on thecloud) may be unable to reach a definitive result and the system mayrespond by requesting ultraviolet light illumination from theillumination hardware 224 in order to generate additional fluorescencespectral information.

Local processor 240 or cloud 250 may be in communication with anallergic reaction monitor 270 for the purpose of correlating pollenexposures with allergic reactions. The benefits possible by combiningexposure and allergic reaction data is described in detail in U.S.patent application Ser. No. 15/061,883.

In an embodiment, the image capture hardware 226 is based on an imagingsensor designed for use in color cameras. The mass market for digitalcameras, including those in smartphones, has resulted in very capablecolor camera sensors at relatively low prices. Such color camerasensors, such as the SON-IMX028 CMOS image sensor by Sony, provides atlow cost rich data for particle detection and discrimination.Furthermore, the spectral richness of data collected with a color camerasensor may be extended by enhancing the capabilities of the illuminationhardware 224; more details are given further below. The use of colorcamera sensors in combination with enhanced illumination hardware isadvantageous for the goal of providing a capable airborne particlemonitoring system 200 in a price range accessible to individual users.

The ability of airborne particle monitoring system 200 to generateactionable information is greatly enhanced by an aspect of user allergicreactions that will in this document be referred to as the “primingeffect.” There is much complexity to the physiological mechanisms bywhich the human immune system reacts to airborne allergenic particles.Fortunately, appreciation of the present system does not require a fulldetailed knowledge of the human immune system. Nevertheless, someunderstanding of immune system “sensitization” or “priming” effects isprovided to fully appreciate the present system. Here we use“sensitization” and “priming” as synonyms for effects where allergenexposure at an earlier time affects the immune systems reaction toallergen exposure at a later time.

In particular, in some cases an allergen exposure at an earlier timedoes not directly lead to user suffering from allergy symptoms but maynevertheless “prime” or “sensitize” the immune system such that the userdoes suffer from allergy symptoms when exposed to allergens at a latertime. More generally, if and how much a current exposure to airborneallergens “aggravate” allergic symptoms depends on the degree to whichthe user's immune system was sensitized or “primed” by past allergenexposures.

Before a user begins to suffer from allergic symptoms, it isparticularly useful to have actionable information to know if and whenone is being exposed to airborne allergens capable of priming one'simmune system. Possible actions include avoiding further allergenexposure or proactively taking medications to reduce suffering fromunavoidable further allergen exposure. The priming effect enablesproactive responses to pollen exposure information.

In the medical literature, a distinction is sometimes made between“sensitization” and “priming effect” where the term “sensitization” isreserved for some types of physiological immune-system mechanisms and“priming effect” for other types of physiological immune-systemmechanisms. Such distinctions can be important to the healthcareprofessional aiding a patient suffering from allergies. However, suchdistinctions are less important to the engineer designing hardware andsoftware of airborne particle monitors. In this document, the terms“sensitization” and “priming” are used as synonyms.

Applicant has appreciated the role of the priming effect in identifyingparticles that may be responsible for a user's allergic reaction. FIG. 3shows an allergic reaction timing diagram along a time axis 310. Let t₀represent an allergic reaction time 320 at which a user starts sufferingfrom an allergic reaction. The start of user suffering from an allergicreaction is likely to be due to what in medical science is known as“early phase” symptoms rather than “late phase” symptoms. This suggestsconsidering immunoglobulin E (IgE) mediated immune system mechanisms asa specific example.

Immunoglobulin E are antibodies produced by the immune system.Generally, if a user has an allergy, the user's immune system overreactsto an allergen by producing antibodies called Immunoglobulin E. Theseantibodies travel to cells that release chemicals, causing an allergicreaction.

More particularly, the immediate cause of the allergic reaction may bethe inhalation of an allergenic pollen or other airborne allergen thatwas recognized by immune cells armed with IgE anti-bodies specific tothe inhaled allergen. These IgE-armed immune cells initiated a chain ofphysiological reactions resulting in symptoms experienced by the user.Allergens recognized by such IgE-armed immune cells may be referred toas “aggravating allergens,” such as an “aggravating pollen.” Moregenerally, aggravating allergens are allergens that are the immediatecause of an allergic reaction.

Some time passes between the inhalation of the aggravating allergen andthe resulting symptoms. Hence the allergic reaction starting at time t₀must be due to exposure to the aggravating allergen sometime before timet₀. However, there is a limit to how long the onset of symptoms can bedelayed with respect to the exposure. Let t_(A) be the earliest time forwhich exposure to the aggravating allergen could lead to symptoms thatdo not occur until time t₀. The period of time between time t_(A) andtime t₀ may be referred to as the aggravation period 340. Theaggravation period 340 is bounded by the aggravation-period start time330 (t_(A)) and the allergic reaction time 320 (t₀).

In some cases, the duration of the aggravation period 340 is generallynot precisely known and might vary with the type of allergen or varyfrom user to user. Nevertheless, it is clearly a time period very shortcompared to one day and long compared to a second. Medical scienceresearch has established reasonable estimates of the duration ofaggravation period 340 to include the range from a few minutes to a halfhour. For example, the aggravation period may range from about 2 minutesto about thirty minutes. This includes, for example, 5, 10, 15, 20, 25,29, or more than 29 minutes. The aggravation period may be less than 2minutes.

The allergic reaction described in the previous paragraph is most likelyto occur if the user's immune system has been primed, that is, only ifthe user's body contains immune cells armed with IgE anti-bodiesspecific to the aggravating allergen. Such priming is the result of anearlier exposure to an allergen that is either the same as theaggravating allergen or is another allergen that cross-reacts with theaggravating allergen. The allergen that primes the immune system may bereferred to as the “priming allergen.” The priming allergen may or maynot be the same as the aggravating allergen.

When a priming allergen is recognized by immune system memory cells, thememory cells cause the user's immune system to start manufacturing IgEanti-bodies specific to the priming allergen. Once manufactured, theseIgE anti-bodies make their way to the immune cells and play a key rolein the aggravation period 340. There is a time delay between userexposure to a priming allergen and the arming of immune cells withcorresponding IgE anti-bodies.

As a result, there is a time after which it is too late for a primingallergen to have contributed to the chain of events leading to anallergic reaction at time t₀. Let t_(E) represent this priming-periodend 350. In some cases, it is not precisely known how far in the pastthe priming-period end 350 occurs, that is, the quantitative value ofthe time difference (t₀−t_(E)) is not precisely known. The value maydepend on both the allergen and the user. Nevertheless, it is clearly atime period very short compared to a week and long compared to an hour.Medical science research has established reasonable estimates for thetime difference (t₀−t_(E)) to include the range from 12 hours to 2 days.For example, the priming-period end time 350 may range from about 12hours to about 2 days. This includes, for example, 15, 20, 25, 30, 35,40, 45, or more than 45 hours. The pre-aggravation period may be lessthan 15 hours.

The priming effect is temporary. After exposure to priming allergensend, the corresponding priming effect fades with time. In biochemicalterms, after exposure to priming allergens end, manufacture ofpriming-allergen specific IgE anti-bodies cease and eventuallypreviously manufactured IgE anti-bodies degrade and disappear. As aresult, there is a time before exposure to priming allergens that is tooearly to explain the primed state of the immune system at the allergicreaction time t₀. Let t_(P) represent this time that may be referred toas the priming-period start time 360.

Exposure to priming allergens during the priming period 370, that startswith the priming-period start time 360 and ends with the priming-periodend time 350, can explain the primed state of the user's immune systemat allergic reaction time t₀ (or more precisely can explain the primedstate of the user's immune system during the aggravation period 340).The duration of the priming period 370 is equal to (t_(E)−t_(P)). Insome cases, it is not precisely known how long this priming period 370is. The value may depend on both the allergen and the user.Nevertheless, it is clearly a time period short compared to a month andvery long compared to a day. Medical science research has establishedreasonable estimates for the time difference (t_(E)−t_(P)) to includethe range from one day to one month. For example, the priming period mayrange from about 3 hours to about 1 month. This includes, for example,1, 2, 4, 6, 15, 20, or 30 days. The priming period may be less than 1day.

The time period between the priming-period end time 350 and theaggravation-period start time t_(A) may be referred to as thepre-aggravation period 380. Allergens inhaled by the user in thispre-aggravation period 380 are too late to be the priming allergencontributing an allergic reaction at time t₀ and too early to be theaggravation allergen contributing to an allergic reaction at time t₀.Lack of allergic reaction during the pre-aggravation period 380 providesevidence that any allergens inhaled during the pre-aggravation period380, even if also present in the aggravation period 340, are not theguilty aggravating allergen. Allergens present in the aggravating period340 but not present in the pre-aggravating period 380 are the primesuspects for aggravating allergens.

In some embodiments, the conclusion of the previous paragraph istentative or preliminary and the user is prompted by the system toanswer questions about medication. It is possible that the user had beentaking medication that suppressed allergic reaction symptoms in thepre-aggravation period 380 and then the medication wore off during theaggravation period 340. In this scenario, allergens detected in thepre-aggravation period 380 remain candidates for being aggravatingallergens.

FIG. 3 and the associated discussion above is idealized in the sensethat transitions at priming-period start t_(P), priming-period end t_(E)and aggravation-period start t_(A) are naïvely presented as sharpboundaries. This idealization is presented for purposes of clarity. Inreality, the boundaries are fuzzy and the transitions are more gradual.For example, assuming a value the priming-period t_(P) of two weeks,common sense tells us not to expect that an exposure to a primingallergen two weeks before allergic reaction time t₀ to be 100 percenteffective while an exposure to a priming allergen two weeks and oneminute before allergic reaction time t₀ to be totally ineffective.

In a specific embodiment, a sophisticated mathematical model is providedwhere the fading of the strength of the priming effect with increasingtimes into the past can be represented by a factor of exp{−(t₀−t)/τ}where t is the time of priming allergen exposure and τ is an exponentialtime constant. However, for an understanding of the basic principles itis not necessary to delve into such mathematical details. Thus, itshould be appreciated that FIG. 3 and associated discussion has beensimplified for clarity of presentation and further mathematicalrefinement can be made without departing from the scope of the presentdisclosure.

The above discussion of FIG. 3 concerns the human immune system andconsidered inhaled allergens. When applying this science to particlecollection machines, it should be kept in mind that allergen exposuresthat are measured by particle collection machines may provide imperfectestimates of exposures of the user to inhaled allergens.

To give a clear example where it is important to distinguish betweenmeasured allergen exposure and true allergen exposure, consider a userthat places a pollen collection machine in a combined kitchen-livingroom, but sleeps in a well-separated bedroom. Furthermore, let us assumeallergenic pollen from outdoors makes its way into the kitchen-livingroom but not the bedroom. After waking up from a good nights sleep, theuser leaves the bedroom and enters the kitchen-living room, and thenshortly thereafter has an allergic reaction at allergic reaction time320.

In this case the user did not inhale the aggravating allergen untilentering the kitchen-living room. The user was not exposed to theaggravating allergen in the pre-aggravation period 380. Nevertheless thepollen collection machine did measure the presence of the aggravatingpollen in the pre-aggravation period 380. To correctly identify theaggravating allergen, one must allow the possibility that theaggravating allergen is detected during the pre-aggravation period 380even if true exposure to an allergen in the pre-aggravation period isreason to eliminate the allergen as the aggravating allergen.

FIG. 4 shows a block diagram of particle monitoring device 105 accordingto one embodiment. The block diagram shows a number of subsystems,processing modules, and components that can be included in the particlemonitoring device. In an embodiment, the particle monitoring deviceincludes quantum dots. The quantum dots are configured emit light havingspectral characteristics corresponding to a particle of interest.Particles collected by the monitoring device are illuminated under thelight emitted by the quantum dots and a color image (e.g., picture,photograph, or snapshot) is taken while the particles are illuminated bythe quantum dots. The image can be analyzed to determine whether theimage includes the particle of interest.

The particle monitoring device shown in FIG. 4 includes a device housingor enclosure 402 and a base 404, connected to the housing. The housingincludes an air intake opening 406 and an air exhaust opening 408.Contained within or inside the housing is a sensor (e.g., microphone)410 connected to an allergic reaction detection subsystem 412, blower414, removable particle collection media 416, collection media motor418, illumination subsystem 420, optical subsystem 422, particleidentification subsystem 424, display 426 connected to the particleidentification subsystem, storage 428, network interface controller 430,Bluetooth communication card 432, global positioning system (GPS) sensor433, housing motor 434, and power source (e.g., battery) 436. There canbe a user-operable power switch so that the device can be turned on,turned off, placed in a standby state, or combinations of these.

The subsystems, processing modules, components and so forth areconnected by a bus system 438. The power source provides electricalpower to the subsystems, processing modules, and components. The powercan be DC power such as that provided by a battery. Using a battery tosupply power facilitates a particle monitor that can be easily placed atany location such as in the user's home or office because the particlemonitor does not have to be located near a wall outlet. The particlemonitor may be placed in an outdoor environment such as the user's yard.A battery-operated device also facilitates the particle monitor beingportable. The user can take the device with them when traveling and usethe device in a hotel room. The battery may be a rechargeable battery ora disposable battery. A particle monitor may include a set of solarcells for recharging the battery. In another specific embodiment, thepower can be AC power.

The sensor can be a microphone that detects sounds local to themonitoring device. Allergic reaction detection subsystem includesdetection logic 440 and an allergic reaction signature database 442. Theallergic reaction signature database stores information includingcharacteristics indicative of an allergic reaction. The signatures canbe information indicating coughing, sneezing, or both. The detectionlogic includes logic to receive a signal from the sensor, compare thesignal to the information stored in the allergic reaction signaturedatabase, and determine whether the user is having an allergic reaction(e.g., user is coughing or sneezing).

The blower is responsible for moving ambient air outside the monitordevice housing, through the air intake opening, into the monitor devicehousing, and then out through the air exhaust opening. The blower may bereferred to a fan.

The removable particle collection media provides a medium for trappingparticles that are airborne or floating in the ambient air. In aspecific embodiment, the collection media includes an adhesive tape. Thetape is flexible so that it can be mounted on or wound upon on a reel orspool. The adhesive tape includes a backing material and an adhesivethat is applied to a side of the backing material. The backing materialcan be made of paper, plastic, plastic film, fabric, polyester, Teflon,nylon, cloth, metal foil, or any other competent material. The adhesivecan be any type of adhesive that can trap particles floating in theambient air. The adhesive may include glue, paste, mastic, rubbercement, or other sticky or tacky substance. The blower directs the flowof air towards or over the collection media. Particles within the airare then trapped by the adhesive-coated side of the tape.

In a specific embodiment, the tape is 3M polyester film tape 850 asprovided by 3M Corporation Maplewood, Minn. Applicants have discoveredthat this particular tape includes features desirable for a particlemonitor. In particular, the polyester film includes a wide temperaturerange resistance (e.g., −50 degrees Celsius to 177 degrees Celsius)which helps to reduce failure caused by film shrinkage or embrittlement.The wide temperature range resistance is desirable because in someembodiments, the monitor device is used outdoors and thus must survivewide temperature fluctuations throughout the day and times of the year.For example, temperatures typically drop during the night and riseduring the day. Applicants have discovered that for applications ofparticle monitoring the tape shows desirable, long lasting cyclicfatigue. This means the tape can be pulled off and coiled again multipletimes to re-examine trapped particles again and again and the tape stillretains very good adhesion.

In a specific embodiment, the adhesive on the tape includes an acrylicadhesive. This is advantageous because it is not water-based and thuscan better survive outdoor environments. For example, outdoorenvironments can be more subject to moisture as compared to indoorenvironments. An acrylic adhesive can tolerate moisture better than awater-based adhesive. In a specific embodiment, the tape includes apolyester film. Properties desirable in the polyester film—including itswide temperature range—is that it can be made very thin, possess veryhigh strength, has high moisture resistance, and is resistant tochemicals and solvents (e.g., will not decompose easily if chemicals orsolvents floating in the air should fall on the tape).

It should be appreciated that 3M polyester film tape 850 is merely oneexample of a tape suitable for use with the particle monitor and inother embodiments, other tapes with properties desirable for theparticle monitor may instead be used. For example, 3M film tape 850includes an adhesion to steel specification according to ASTM testmethod D-3330 of 31.5 N/100 mm). The collection media motor is designedwith sufficient power to advance and uncoil the tape. Applicants havefound that a lower adhesion to steel value can be desirable (e.g., about15.7 N/100 mm) because less power is required to advance and uncoil thetape.

In a specific embodiment, a color of the tape is black or a dark color.An advantage of using black or a dark color is that light is less likelyto reflect or bounce off the tape as compared to lighter colors (e.g.,white). For example, a technique of the system includes capturing imagesof the particles under different specified illumination conditions.Light (e.g., white light) bouncing off the tape and into the camerasensor may skew the images and, in particular, the colors captured inthe images. Particles may be examined using a technique referred to asall-angle. In another specific embodiment, the tape is transparent or atleast partially transparent. A transparent tape allows for back-sideillumination (e.g., illuminating from below the tape). In anotherspecific embodiment, a tape upon which the particles are collected doesnot include an adhesive. In this specific embodiment, the tape includesan electrostatic surface. The tape may include, for example, aconducting film. The electrostatic surface attracts particles that comeinto close proximity to the tape. For example, if the particles arepositively charged, the tape can be negatively charged.

In a specific embodiment, a removable cartridge is provided which housesthe adhesive coated tape. The cartridge houses a supply reel, an uptakereel, and the adhesive coated tape. An end of the tape is connected tothe supply reel. An opposite end of the tape is connected to the uptakereel. The adhesive coated tape is wound upon the supply reel and spentportions of the tape upon which particles have been trapped are woundonto the uptake reel. The cartridge may further include anidentification tag such as a radio frequency identification tag (RFID)tag, machine readable code (e.g., barcode, quick response (QR) code), orother label. Depending upon the type of tag, the tag may be attached toa body of the cartridge (e.g., via glue), or printed onto the body ofthe cartridge. The particle monitor may include a corresponding reader.The identification tag allows the particle monitor to uniquely identifythe cartridge. In another specific embodiment, a removable cartridgehouses tape that does not include an adhesive-coated surface. Forexample, the tape may include an electrostatically charged surface whichdoes not have adhesive material but rather an electrically conductivesurface

In another specific embodiment, the collection media includes a rigiddisc. A side of the disc is coated with an adhesive to trap the airborneparticles that enter the monitoring device. The disc exposes differentregions around an annulus so that particles are trapped within aparticular region. The disc may be made of plastic, nylon, metal, or anyother rigid material. In another specific embodiment, the collectionmedia includes adhesive-coated glass slides. In each embodiment, theadhesive coated tape (or other particle collection media such asadhesive-coated glass slides or adhesive-coated disc) may be removedfrom the particle collection device and fresh media inserted into theparticle collection device. Anywhere a glass slide may be used, aplastic slide is likely to be an equally viable option. Removed mediacontaining captured particles may be subjected to laboratory inspectionand testing, archived for possible future laboratory inspection andtesting, or both.

The collection media motor is responsible for advancing the collectionmedia. For example, in an embodiment, the collection media includes acartridge having a supply reel, an uptake reel, and an adhesive coatedtape wound about the supply reel and connected to the uptake reel. Uponcollecting some airborne particles on a portion of the adhesive coatedtape, the media motor can advance the tape so that new particles can betrapped on another portion of the adhesive coated tape. The portionhaving the previously trapped airborne particles can be advanced to theparticle identification subsystem for imaging and examination.

The collection media motor may include a counter that tracks a positionof the tape. The position of the tape can be associated with the image.Storing the position information allows the tape to be later advanced(or unwound) to the same position at which the image was taken andadditional analyses to be performed. The counter may count a number ofunits between a reference point on the tape (e.g., a beginning of thetape or an ending of the tape) and a location of the tape at which theimage was taken. The units may be distance-based. For example, thelocation of the tape may be a distance as measured from the beginning ofthe tape.

The illumination subsystem includes various optical elements forgenerating and emitting light or radiation (e.g., visible light,ultraviolet light, infrared, or combinations of these) into theparticles that have collected on the collection media. The illuminationsubsystem includes one or more light sources (e.g., two light sources).Each light source includes one or more light emitting elements.

In a specific embodiment, a lighting element includes a light emittingdiode (LED). A light source may include a cluster of light emittingelements such as a cluster of LEDs (e.g., two or more LEDs). A clustermay include any number of light emitting elements such as LEDs. Forexample, a cluster may include one, two, three, four, five, six, seven,eight, or more than eight LEDs. In another specific embodiment, alighting element includes a laser diode. There can be a combination ofdifferent types of light emitting elements such as a combination of LEDsand lasers.

The illumination subsystem may include lenses, filters, diffusers, orcombinations of these for directing or modifying the light as desired.For example, a diffuser may be used to spread out the light from alighting element and provide a soft light. A diffuser can help to ensurethat the area around the collected particles is illuminated. In aspecific embodiment, the illumination system includes optical fiber. Theoptical fiber can be used to collect light emitted by a light source anddirect the light onto the collected particles.

In an embodiment, the illumination subsystem includes a first lightsource 444, and a second light source 446. In an embodiment, at leastone of the first or second light sources includes quantum dots. In aspecific embodiment, the quantum dots are suspended or dispersed withina film. The film can include a material in the form of a thin flexiblesheet. The film is positioned to receive and convert the light from alighting element. The film may be positioned at a distance from thelight source or proximate or even inside the light source. For example,the quantum dots (or a layer having the quantum dots) may be placed sothat they contact a surface of an LED chip. (see, e.g., FIG. 23). Inanother specific embodiment, the quantum dots may be mixed into anadhesive of the adhesive coated tape of the collection media. In anotherspecific embodiment, the quantum dots may be placed on or into thebacking material of the adhesive coated tape. In another specificembodiment, instead of absorbing and re-emitting light by quantum dots,an electrical current is passed through quantum-dots resulting in directgeneration of light of the desired wavelength. Further discussion isprovided below.

The optical subsystem includes various optical elements for capturingone or more images of the collected particles while the collectedparticles are being illuminated or radiated by the illuminationsubsystem. In an embodiment, the optical subsystem includes a microscopeincluding a camera sensor 448 and lens assembly 450. A microscope is anoptical instrument having a magnifying lens or a combination of lensesfor inspecting objects too small to be seen or too small to be seendistinctly and in detail by the unaided eye. The lens assembly includesa set of lenses for bringing the collected particles into focus,magnifying the collected particles, or both. The camera sensor collectslight scattered or reflected back from the particles to capture imagesor photographs.

The particle identification subsystem includes an image recognitionengine 452, particle reference library 454, and context informationacquisition unit 456. A particle identification manager 458 manages theparticle identification or discrimination process.

The particle reference library stores reference information identifyingdifferent types of airborne particles. In a specific embodiment, thereference information includes particle-discrimination algorithmparameters. Optionally, these particle-discrimination algorithmparameters are determined by machine learning algorithms and a learningset of reference files that includes images including color photographsof different types of known particles. The machine learning algorithmsthat determine the particle-discrimination algorithm parameters may runlocally, on the cloud, or both but the cloud is generally preferred inorder to reduce the cost of computing hardware in the local device. Theset of learning files may include reference images of tree pollen, grasspollen, weed pollen, mold spores, cat dander, dog dander, and so forth.Table A below shows an example of a data structure that may be used tostore the reference information.

TABLE A Filename Description grass_pollen.jpg Picture of grass pollens.mold.jpg Picture of mold spores. . . . . . .

A first column of the table is labeled filename and lists the variousfiles stored in the particle reference library. A second column of thetable includes metadata (e.g., a description) that identifies the objectin the corresponding file.

In an embodiment, the image recognition engine receives the image of thecollected particles taken by the optical subsystem and analyzes theimage using particle-discrimination algorithm parameters it previouslyreceived from the cloud. For example, particle-discrimination algorithmsrunning in the particle identification subsystem may identify thecollected particle as grass pollen. Some examples of parameters that maybe considered in a particle-discrimination algorithm includeautofluorescence properties (e.g., intensity of autofluorescence), size,shape, length of polar axes, length of equatorial axes (or diameter),ratio of polar axis to equatorial axis (P/E ratio), number of apertures,type of apertures, shape of apertures, position of apertures, lack ofapertures, color characteristics, geometrical features, type of symmetry(e.g., radial symmetry or bilateral symmetry), lack of symmetry, otherparameters, weights, or combinations of these. One or more of theseparameters may be derived or extracted from optical system measurements,specified as a threshold, and then used as a discrimination algorithmparameter to discriminate particles.

The image recognition engine may use any competent technique orcombination of techniques for recognizing the particles imaged by theoptical subsystem. Some examples of image recognition techniques includeedge detection, edge matching, changes in color, changes in size,changes in shape, divide-and-conquer searches, greyscale matching,gradient matching, histograms of receptive field responses, large modelbases, interpretation trees, hypothesize and test, post consistency,pose clustering, invariance, geometric hashing, scale-invariant featuretransform (SIFT), and speeded up robust features (SURF), among others.

The context information acquisition unit is responsible for obtainingcontext information associated with the particles that have beencollected by the monitoring device. The context information may be basedon a geographical location of the collected particles, a time and dateof the collection, or both. In an embodiment, the context informationincludes blooming data. For example, spring blooming plants include oak,birch, hickory, and pecan. Fall blooming plants include ragweed. Thecontext information may include weather conditions, temperature, windspeed, wind patterns, and so forth.

The context information may include a listing of particle types thathave been identified by other nearby particle monitors, mobile drones,or both. For example, nearby particle monitors may include particlemonitors that are within a specified radius of the requesting particlemonitor. The radius may be, for example, 50, 100, 500, 1000, 2000, ormore than 2000 meters. The radius may be less than 50 meters. The radiusmay be configurable such as by a user or administrative user. The radiusmay be determined dynamically. For example, the radius may varyproportionally to current wind speed as high winds can increase thelikelihood of particles being carried into the local environment fromremote areas.

The context information is used by the particle identification subsystemto help narrow the list of candidate particle types. Results of theparticle identification subsystem may be outputted to the display,recorded in a log, or both.

The storage may include a particle identification log 460, imagesrepository 462, and image index 464. The particle identification logrecords identifications of particles as determined by the particleidentification subsystem. Table B below shows an example of informationthat may be recorded in the log.

TABLE B Image Context Info Particles File File Present TimestampLocation 001.jpg Context1.txt Grass pollen April 10, 2016, 11:34 45Appleseed Drive, AM Santa Rosa, CA 94555 002.jpg Context2.txt Grasspollen April 10, 2016, 1:36 45 Appleseed Drive, PM Santa Rosa, CA 94555003.jpg Context3.txt Mold spores April 11, 2016, 2:00 45 AppleseedDrive, PM Santa Rosa, CA 94555

In the example shown in table B above, a first column of the table liststhe name of the file containing the image of the collected particles. Asecond column lists the name of the file containing the contextinformation that may be associated with a geographical location of thecollected particles, time and date of the collected particles, or both.The context information may be formatted as a text file, ExtensibleMarkup Language (XML) formatted file, or in any other file format asdesired. A third column of the table stores a timestamp indicating atime and date that the particles were collected. A fourth column of thetable stores a location of the particle collection.

It should be appreciated that the data shown in table B above is merelyan example of some of the metadata information associated with particleidentification that may be stored in the database. In a specificembodiment, a particle information packet and particle informationpacket history is stored. Further details are provided below.

The images repository stores the image files generated by the opticalsubsystem. The files store digital images of the particles that havebeen captured. The files may include raw image files (e.g., digitalnegatives), raster images, bitmapped images, or combinations of these.The files may be formatted using any type of image file format (e.g.,jpeg, exif, tiff, gif, bmp, png, and so forth).

The image index database stores metadata associated with the imagefiles. The metadata may include, for example, image filenames, time anddate that the image was taken, geographical location data, opticalsettings, and so forth. The metadata may include a description orspecification of the lighting conditions, as provided by theillumination subsystem, under which the images were made. For example,the metadata may indicate that a first image was taken while particleswere illuminated by white light, a second image was taken while theparticles were illuminated by red light emitted from quantum dots, athird image was taken while the particles were illuminated byultraviolet light, a fourth image was taken while the particles wereilluminated by infrared light, and so forth. The index can be accessedand searched.

In a specific embodiment, the particle identification log, particleimage files, image index, or combinations of these are transmitted fromthe particle monitor to the cloud server for further review, archivalstorage, backup. For example, the particle image files may betransmitted to the cloud server periodically or in batch such asnightly, weekly, or at any other frequency or time as desired. Once theimage files have been transmitted to the cloud server, the image filesmay be deleted from the particle monitoring device. Deleting the imagesfrom the particle monitoring device frees up storage space for newimages.

The GPS sensor provides geographical location information. Thegeographical location information allows the images of the collectedparticles to be tagged with the location of collection. As discussed,the location information is used to obtain context information such asthe plants, flowers, or other vegetation currently in bloom at thegeographical location of collection, weather conditions, identify othernearby particle monitors, or combinations of these.

The Bluetooth communication card or chip allows for a wireless pairingof the particle monitor and a user's mobile device. Bluetooth includes acommunication protocol that allows for communicating over shortdistances (e.g., about 10 meters). The wireless pairing allows theparticle monitor device and mobile device to exchange communication andother information. For example, in a specific embodiment, the particlemonitor transmits to the mobile device a message including anidentification of a particle that was collected. It should beappreciated that Bluetooth is merely one example of a standard forwireless communication. Other embodiments may include othercommunication standards in addition to or instead of Bluetooth such asWiFi.

In another specific embodiment, some of the components shown in theexample of the particle monitor shown in FIG. 4 may be omitted and thedata they provide may be fulfilled by the user's mobile device. Forexample, the sensor and allergic reaction detection subsystem may beomitted in another embodiment of the particle monitor. In this specificembodiment, the allergic reaction detection subsystem may be installedonto the mobile device as a mobile application program or “app” and thesubsystem may rely on the sensor provided by the manufacturer of themobile device to detect user actions, motions, and so forth. In thisspecific embodiment, when the “app” determines that the user hassuffered an allergic reaction, the app sends a notification of theallergic reaction to the particle monitor so that the event can belogged and recorded.

Bluetooth (or WiFi) can further be used to determine that a user hasentered the local environment in which the particle monitor is locatedby detecting the specific mobile device that the user may have on theirpresence. For example, a mobile device may be identified based on itsInternational Mobile Equipment Identifier (IMEI), Media Access Control(MAC) address, or both. The IMEI includes a string of numbers that isunique for every device. A MAC address uniquely identifies wirelesstransmitters such as Bluetooth and WiFi chips that may be located in thedevice.

Detecting that the user has entered the local environment can be used tohelp move the particle monitor from a standby mode to an active mode.Conversely, detecting that the user has left the local environment canbe used to help move the particle monitor from an active mode to astandby mode. A user does not have to remember to turn on the particlemonitor each time the user enters the room (or to turn off the monitoreach time they leave the room).

When the particle monitor is in standby mode, the particle monitorconsumes less power (e.g., battery power) as compared to when theparticle monitor is in active mode. The standby mode of operation helpsto conserve power. Low power consumption is desired to minimize or lowerelectricity costs for the user and reduce the carbon footprint of thedevices. For example, when the particle monitor is in standby mode, theparticle monitor may not perform particle collection. When the particlemonitor is in the active mode, the particle monitor may perform particlecollection such as on a periodic basis. In a specific embodiment, amethod includes receiving at a particle monitor a signal from a mobiledevice of a user indicating that the user is in a local environment ofthe particle monitor, transitioning in response to the signal from astandby mode to an active mode where the active mode includes collectingparticles in the local environment, detecting based on an absence of thesignal that that the user has left the local environment, and inresponse to the detection, powering down from the active mode to thestandby mode where the standby mode does not include the collectingparticles.

A power subsystem of the particle monitor may include a low-batteryindicator unit. When the available battery power drops below a threshold(e.g., 20 percent battery remaining), the low-battery indicator unit cantransmit a notification such as text message notification to the user'smobile device to notify the user that the particle monitor should berecharged.

The detection of a particular device can be used to identify differentusers of the particle monitor as long as each user has their own mobiledevice. For example, a user may be part of a family in a house whereother family members also suffer from allergies. The particle monitorcan track which user is currently in the local environment so thatparticle collections can be associated with a particular user. Beingable to distinguish which user is currently in the local environment ofthe particle monitor helps to identify the specific airborne allergensthat may affect each different user.

The housing motor turns or rotates the particle device housing about thebase. The turning allows the air intake opening to pull in ambient airfrom different directions so that there is a good or representativesampling of air. The housing motor can be used to ensure that the airintake openings are aligned with a direction of wind so that airborneparticles in the wind will enter through the air intake opening.

In a specific embodiment, the power source includes one or morebatteries. The battery may be a rechargeable battery. Examples ofrechargeable batteries include nickel cadmium (NiCd) batteries, nickelmetal hydride (NiMH) batters, lithium ion (Li-ion) batteries, andothers. When the rechargeable battery within the particle monitor isdepleted, the batteries can be recharged by an AC adapter and cord thatmay be connected to the particle monitor.

Instead or additionally, the particle monitor may include a universalserial bus (USB) port. The USB port allows the particle monitor to beconnected to a computer such as a desktop computer for charging. Theport may also be used to configure the particle monitor via the desktopcomputer, transfer data from the particle monitor to the desktopcomputer, transfer data from the desktop computer to the particlemonitor, or combinations of these. In another specific embodiment, thepower source includes one or more disposable batteries.

The network interface controller provides the gateway to communicatewith the mobile device, server, or both. In an embodiment, the networkinterface is connected to the Internet. The network interface controllermay include an antenna for wireless communication, an Ethernet port toconnect to a network via a cable, or both.

The housing may be made from a material such as plastic, nylon, metal,wood, or combinations of these. In a specific embodiment, the housing ismade of plastic. A material such as plastic is desirable because aplastic housing allows for the passage of radio waves so that theparticle monitor can communicate wirelessly. For example, an antennalocated inside a plastic housing will be able to receive and transmitwireless signals through the plastic housing. Plastic is also relativelyinexpensive to form and manufacture. In other cases, however, a metalhousing may be desired. Metal can be less likely to crack as compared toplastic and users may prefer the aesthetic appearance of metal. Inembodiments where the housing is made of metal, the antenna may belocated or embedded on an outside surface of the housing.

FIG. 5 shows another specific embodiment of particle monitor 105. Theparticle monitor shown in FIG. 5 is similar to the particle monitorshown in FIG. 4. The particle monitor shown in FIG. 4, however, includesa removable particle collection media with quantum dots 505. In aspecific embodiment, the collection media is contained within acartridge. The cartridge includes a pair of spools and a tape woundabout the pair of spools. The tape includes an adhesive and a backingmaterial where the adhesive has been applied to a side of the backingmaterial. In a specific embodiment, the quantum dots are within thebacking material. In another specific embodiment, the quantum dots arewithin the adhesive. In another specific embodiment, the quantum dotsmay be included in a guide structure within the cartridge. Furtherdetail is provided below.

FIG. 6 shows a block diagram of a remote cloud server 605 according to aspecific embodiment. The server includes a particle identificationupdate module 610, reference library update module 615, contextinformation processing unit 620, central particle image repository 625,central particle identification log repository 630, context informationdatabase 635, database 640 storing information about various registeredparticle monitors that have been deployed, and particle identificationserver engine 645. A technician console 650 is connected to the server.

The particle identification update module is responsible for sendingcode updates to the various particle monitors that have been deployedthroughout the world. The code updates may include firmware updates. Theupdates help to ensure that each monitor is equipped with the mostrecent versions of the algorithms for particle identifications.

The reference library update module is responsible for sending new orupdated reference images of particles. For example, as new referenceimages of particles are made, these reference images can be distributedto each of the various particle monitors.

The context information database stores context information such asblooming periods of various plants and flowers, geographic location datafor the various plants and flowers, weather conditions, and so forth.The context processing unit can receive from a particle monitor arequest for context information where the request specifies ageographical location of the particle monitor, time of particlecollection, or both. The context processing unit can access the contextinformation database to retrieve a subset of relevant contextinformation corresponding to the geographical location, time, or bothand transmit the subset of relevant context information to therequesting particle monitor.

The central particle image repository stores images of particles thathave been taken by the various particle monitors and transmitted to thecloud server. The images can be accessed and viewed via the technicianconsole by a human technician 655. The central image repository (orother central repository) may further store the analysis results fromthe various particle monitors. This allows the technician to performmanual spot checks of the analysis to help ensure that the particleidentifications made by the particle monitors are accurate. The imagerepository further allows the technician make a manual identification ofparticles by reviewing images where the local particle monitor is unableto make a satisfactory identification.

The central particle log repository stores particle identification logsgenerated by the various particle monitors and transmitted to the cloudserver. As discussed, the particle identification logs can includelistings of particle types that have been identified and associatedmetadata such as a time and date of particle capture, location ofparticle capture, and so forth.

The deployed monitors database stores information about the variousparticle monitors that have been deployed throughout the world. Thedatabase may be referred to as a particle monitor registration database.The information may include, for example, a geographical location of aparticle monitor, particle identification logs containing informationabout particles captured by the particle monitor, images or an index toimages taken by the particle monitor, user information (e.g., user firstname, user last name, user email address, or user mailing address) dateparticle monitor was purchased, device serial number, firmware version,and other information. Table C below shows an example of informationthat may be stored in the deployed monitor database.

TABLE C Monitor ID Location Particle ID Log Images Captured 312945 45Appleseed 2016-05- 2016-05- Drive, 12_31245_log.txt 12_31245_image1.jpgSanta Rosa, . . . . . . CA 94555 987431 32 Pear Lane, 2016-05- 2016-05-Philadelphia, 12_987431_log.txt 12_987431_image1.jpg PA 19042 . . . . ..

A first column of the table lists an identifier that uniquely identifiesa particle monitor. A second column of the table lists a location wherethe particle monitor is located. In this example, the location includesa street address. The location may instead or additionally includelongitude and latitude coordinates, or any other value or set of valuesthat identifies a geographic location of the particle monitor. A thirdcolumn of the table lists particle identification logs received from theparticle monitor. A fifth column of the table lists particle imagesreceived from the particle monitor.

The particle identification server engine is responsible for performinga server-side analysis of the imaged particles. For example, the cloudserver may have access to computing resources not available locally atthe particle monitor. The particle monitor is designed to be arelatively compact and inexpensive device. The server, however, mayinclude processors more powerful than those at the particle monitor, beable to execute more complex particle identification algorithms than theparticle monitor, and so forth.

In an embodiment, when the particle monitor is unable to identify acaptured particle, the particle monitor notifies the server. The servercan coordinate with the particle monitor in making an identification.For example, the server may use a different set of algorithms to analyzethe particle images transmitted from the particle monitor to the server.Based on the analysis, the server may issue instructions to the particlemonitor for additional images or other data. The instructions mayinclude a request to capture additional images of the particles. Therequest may include a specification of the conditions or parametersunder which the particles should be imaged. For example, the request mayspecify a focal depth at which an image should be taken, illuminationunder which the image should be taken, and so forth.

It should be appreciated that the cloud server is merely representativeof an embodiment. There can be multiple cloud server and storagesystems. Context information or portions of context information may beprovided by one or more third parties. For example, weather conditionsmay be obtained from a third party that offers weather provider services(e.g., AccuWeather).

FIG. 7 shows a block diagram of a mobile device 705 according to aspecific embodiment. In the example shown in FIG. 7, the mobile deviceincludes a display 710 and other hardware components such as amicrophone, accelerometer/gyroscope, camera, GPS, memory, processor,storage, network interface, antenna, speaker, and battery. The mobiledevice includes a particle identification app 750 that allows the mobiledevice to be paired with a particle monitor as described herein. Theparticle identification app can display messages from the particlemonitor such as a message 755 specifying the particles that have beencollected and identified, e.g., “Grass pollen detected May 7, 2016,10:32 AM at home.”). The particle app may or may not include an allergicreaction detection subsystem or logic 760.

FIG. 8 shows an overall flow 805 of a system for collecting andidentifying or discriminating airborne particles. Some specific flowsare presented in this application, but it should be understood that theprocess is not limited to the specific flows and steps presented. Forexample, a flow may have additional steps (not necessarily described inthis application), different steps which replace some of the stepspresented, fewer steps or a subset of the steps presented, or steps in adifferent order than presented, or any combination of these. Further,the steps in other embodiments may not be exactly the same as the stepspresented and may be modified or altered as appropriate for a particularprocess, application or based on the data.

In a step 810, a particle monitor collects, over a period of time,particles that are airborne in an environment that is local to a user.The local environment may include the user's house, a room in the user'shouse, the user's backyard, the user's front yard, the user's office,and the like. The local environment may be an area within about a 10meter radius from the particle monitor.

In a step 815, an allergic reaction of the user is detected. In aspecific embodiment, the allergic reaction detection subsystem receivesvia one or more sensors local to the user information indicating thatthe user may have experienced a physiological event.

The information may include, for example, an audio signal generated by amicrophone local to the user, motion data generated by an accelerometerattached to the user, or both. The received information is compared tothe database storing allergic reaction signatures. The signatures mayinclude coughing sounds, sneezing sounds, coughing motions (e.g., motiondata indicating a heaving of the chest or motion data indicating acovering of the mouth), and the like.

The signatures may be generated as part of a configuration or initialsetup process in which the system prompts the user simulate an allergicreaction, records user activity associated with the simulated allergicreaction, and generates allergic reaction signature data based on therecorded user activity. Allergic reaction signatures may be generatedfor a particular user. This helps to ensure good accuracy in identifyingan allergic reaction because the specific sounds, movements, or both ofan allergic reaction may differ among individuals. In another specificembodiment, the system may store a set of default or generic allergicreaction signatures so that users are not required to simulate anallergic reaction as part of the configuration.

In another specific embodiment, upon detecting a potential allergicreaction, the system prompts the user to confirm whether or not theyhave indeed just suffered an allergic reaction. For example, the systemmay detect what appears to be a coughing or sneezing sound. In response,the system may display on an electronic screen of the user's mobiledevice a message, “Potential allergic reaction just detected. Pleaseconfirm ‘Yes, I just had an allergic reaction,’ or ‘No, that wasn't anallergic reaction.’” Upon receiving a confirmation of an allergicreaction, the system classifies the event as an allergic reaction.

In a step 820, upon determining that the user has suffered an allergicreaction, the time period over which particles have been collected ispartitioned into a set of sub-periods. The sub-periods include anaggravation period, pre-aggravation period, and priming period.

In a step 825, airborne particles collected during one or more of thesub-periods are analyzed and identified. In a specific embodiment, theanalysis includes emitting first light to illuminate the collectedparticles, capturing a first image of the particles while the particlesare illuminated under the first light, emitting second light, differentfrom the first light, to illuminate the collected particles, andcapturing a second image of the particles while the particles areilluminated under the second light. The emitted second light includeslight emitted from a set of quantum dots. The emitted light enters thecollected particles and, depending up on the absorption characteristicsof the particles, may or may not be reflected back. The images arestored and analyzed to identify the particles that have been collected.There can be an any number of different illumination conditions andimages made. Generating more images of the particles under differentillumination conditions can be used to provide greater accuracy inidentifying the collected particles.

In a step 835, particles identified in one sub-period are compared withparticles identified in another sub-period to identify a particleresponsible for the allergic reaction. For example, as discussed above,a particle detected during the aggravation period but not detectedduring the priming period may indicate that the particle is notresponsible for the allergic reaction.

FIG. 9 shows another block diagram of particle monitor 105 according toone embodiment. In the example shown in FIG. 9, a particle monitor 905includes a housing 910 mounted to a base 915. The housing includes anair intake opening 920, an air exhaust opening 925, and a cartridge slotopening 930. There can be a door connected to the cartridge slot openingvia a hinge. The door can open into the cartridge slot. Shown inside thehousing are a battery or power supply 935 which is connected tocircuitry and logic 940 which in turn is connected to a blower 945,first motor 950, second motor 955, optical subsystem 960, illuminationsubsystem 965, communications interface 970, and sensor 975 (e.g.,microphone). The sensor is shown in broken lines to indicate that it isnot included in some embodiments.

Further shown in FIG. 9 is a removable particle collection cartridge980. The particle collection cartridge includes a reel of tape media.The tape media is wound about the reel and includes an adhesive tocollect airborne particles (e.g., pollen or mold spores). The collectioncartridge is removable from the collection device. That is, a user canremove the cartridge from the collection device without breaking ordestroying the device. There can be an eject button that the user canpress to eject the cartridge from the particle collection device. Forexample, when the collection cartridge is full (or as desired), the usercan remove the collection cartridge from the collection device throughthe cartridge slot opening. The user can then install a new collectioncartridge by inserting the new collection cartridge into the collectiondevice through the cartridge slot opening. The user can then mail theremoved collection cartridge—which contains the collected airborneparticles—to a laboratory for a further in-depth analysis.

The design of the particle monitor and cartridge allows for a veryflexible approach for collecting and analyzing particles. In particular,in another specific embodiment, the cartridge is used for surfaceparticle sampling. Surface particle sampling may be instead of or inaddition to airborne pollen or particle sampling. The cartridgefacilitates a collection system or mechanism that is handheld and easilyportable. A user can hold a body of the cartridge in their hand,position an opening or slot of the cartridge through which a portion ofthe tape is exposed, and press the slot against a surface of an object.Particles on the surface may then be transferred from the surface of theobject to the exposed portion of the tape. The user can then insert thecartridge into the particle monitor for analysis of the particles thathave been collected on the tape.

In a specific embodiment, a handheld portable particle monitor withremovable collection cartridge is provided. In this specific embodiment,the monitor is a relatively small, lightweight, inexpensive, and compactdevice. The monitor is powered by a battery. This allows the monitor tobe easily portable and mobile because the monitor does not have to beconnected to an electrical outlet to operate. A user can take themonitor and cartridge to an environment where there might not be anyelectrical outlets such as to a vineyard, farm, plantation, ranch,forest, or other field environment to collect and analyze airborneparticles, surface-borne particles, or both.

Particles that may be associated with diseases including agriculturaldiseases, plant diseases, animal diseases, and so forth can be easilycollected, analyzed, and identified in the field before widespreaddamage occurs. The handheld particle monitor may include a handleconnected to a body of the monitor so that the monitor can be carried.Instead or additionally, at a least a portion of an outside surface ofthe monitor body may be textured or knurled to facilitate carrying.Further, because the monitor may be used in outdoor environments, aswell as indoor environments, the monitor may include seals to provide aweather-resistance or weather-proof construction. Examples of sealsinclude O-rings, gaskets, all-weather glue, and others.

The particle collection device may include an electronic screen todisplay a status associated with operations of the particle collectiondevice (e.g., “collection cartridge tape 80 percent full,” “analyzingparticles,” “device error,” “transmitting data to remote cloud server,”“firmware update in progress, please wait,” and so forth). There can bestatus lights such as LED status indicators. The particle collectiondevice may include an input device such as a keypad through which theuser can power the device on or off, configure various settings andparameters such as collection frequency (e.g., sample air every 5minutes, every 10 minutes, every 20 minutes, or every 30 minutes), othersettings, and so forth. Instead or additionally, at least some settingsmay be configured remotely.

The blower may include a fan and is responsible for creating a vacuum inwhich air is sucked into the collection device thorough the air intakeopening. A flow path of air is directed to the particle collectioncartridge. Particles that may be floating or suspended in the air aretrapped by the adhesive tape of the particle collection cartridge. Theair then exits the collection device through the air exhaust opening.

The first motor operates to rotate the housing of the collection deviceabout the base. The collection device may include an airflow sensor orairflow direction sensing unit that detects a direction of the flow ofthe ambient air. Based on the direction of the airflow, the first motorcan rotate the collection device to orient or align the air intakeopening with a direction of the flow of the ambient air. Instead oradditionally, the first motor may be configured to continuously orperiodically rotate to obtain good representative samples of the ambientair.

The second motor engages the reel of the tape media to unwind theadhesive coated tape media. For example, as airborne particles such aspollen become trapped in a portion of the adhesive coated tape, thesecond motor can unwind the reel to expose a new portion of the adhesivecoated tape upon which new airborne particles can be collected.

The second motor is further responsible for advancing the tapecontaining the trapped particles to the optical and illuminationsubsystems. One or more lighting sources of the illumination subsystemilluminate the trapped particles while a camera sensor of the opticalsystem captures images (e.g., pictures) of the trapped particles foranalysis and identification.

The communications interface is responsible for communications with, forexample, the mobile device, remote cloud server, or both. Thecommunications interface may include an antenna for wirelesscommunication. The sensor (e.g., microphone) may be as described above.

FIGS. 10-18 show various views of particle monitor device 105 (andparticle collection cartridge) according to an embodiment. FIGS. 10through 18 illustrate in more mechanical design detail a specificembodiment of an airborne particle monitoring device. FIG. 10 shows anexterior view of a particle monitoring device 1000 including acylindrical housing 1010 that contains most of the device components aswell as a base 1020. Cylindrical housing 1010 contains an air-intakeslot 1030 that may be a few centimeters in length and a width thatvaries from about 3 millimeters (mm) to about 1 mm in funnel-likefashion as it penetrates the thickness of the cylindrical housing 1010.The length of the air-intake slot may range from about 3 centimeters(cm) to about 10 centimeters. This includes, for example, 4, 5, 6, 7, 8,9, or more than 10 centimeters. The length may be less than 3centimeters.

The cylindrical housing 1010 also contains a particle-media-cartridgedoor 1040 that may be opened in order to insert or remove particle mediacartridges such as shown in FIG. 11 and discussed below. The air-intakeslot is adjacent or next to the cartridge door. A shape of the cartridgedoor includes a rectangle. The cartridge door is oriented verticallywith respect to a central axis passing through the particle collectiondevice. The door may be positioned closer to the base of the monitorthan the top of the monitor.

As shown in the example of FIG. 10, in embodiment, the cartridge doorincludes a top door edge, a bottom door edge, opposite the top dooredge, and left and right door edges extending between the top and bottomdoor edges. The bottom door edge is closer to the base than the top dooredge and the bottom and top door edges are parallel to each other. Theleft and right door edges are opposite and parallel to each other.

The air-intake slot includes a top intake edge, a bottom intake edge,opposite the top intake edge, and left and right intake edges extendingbetween the top and bottom intake edges. The bottom intake edge iscloser to the base than the top intake edge and the bottom and topintake edges are parallel to each other. The left and right intake edgesare opposite and parallel to each other.

In an embodiment, the air-intake slot is located relatively close to thecartridge door. This helps to allow particles in the air enteringthrough the air-intake slot to be collected on the media cartridge. Forexample, an arc length as measured clockwise along the outside surfaceor circumference of the cylindrical housing from the left door edge tothe right intake edge may be A1. An arc length as measured clockwisealong the outside surface or circumference of the cylindrical housingfrom the right intake edge to the left door edge may be A2. Arc A1 maybe less than arc A2. A ratio of A1 to A2 may be about 1:80. The ratio,however, may vary greatly and in other embodiments may be about 1:40,1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:85, 1:90, 1:95, 1:100,1:105, 1:110, 1:115, or 1:120. In an embodiment, the air-intake slot isbetween a first line or arc about the housing extending from the topdoor edge and a second line or arc extending from the bottom door edge,the first and second lines being parallel to each other. The air-intakeslot may be shaped as a rectangle, oval, obround, circle, or any othershape as desired. There can be multiple air-intake slots (e.g., two,three, four, five, or more than five air-intake slots).

The cylindrical housing 1010 and its contents may rotate about itscylindrical axis with respect to the base in order to orient theair-intake slot 1030 in a desired direction. In some cases, it may bedesired to systematically vary the orientation of the air-intake slot1030 in order to average over all directions. Alternatively, theparticle collection device 1000 may orient itself so that the air-intakeslot 1030 faces upwind to any breeze or other flow of ambient air. Inthis latter case, it is advantageous for the particle collection device1000 to include wind or airflow sensors. Visible in FIG. 10 are two offour wind-detector recesses 1050 in which may be mounted airflow sensorsin such a way that they are both exposed to ambient airflow andmechanically protected from accidental impact or contact. In a specificembodiment, a wind-detector recess includes a cantilever deflectiondetector. Wind detectors of many types, including hot-wire airflowdetectors, cantilever deflection detectors, or both may be placed in thewind-detector recesses 1050.

The generally cylindrical elongated shape of the housing helps to reduceinterference with other external objects (e.g., furniture) when thecollection device rotates to sample airborne particles such as pollen,mold spores, or both from different directions. In this specificembodiment, a cross-sectional shape of the housing includes a circle. Inother specific embodiments, a cross-sectional shape of the housing mayinclude a square, rectangle, oval, triangle, or any other shape.

FIGS. 11-13 illustrate a particle media cartridge 1105 that may beloaded or removed from the particle collection device 1000 via theparticle-media-cartridge door 1040. The cartridge includes a media forcapturing particles as well as a cartridge body 1110. In this specificembodiment the media includes an adhesive coated tape, however, in otherembodiments a different media may be used such as adhesive coatedslides. The cartridge body 1110 includes a tape guide structure or wall1120 that includes portions including an air-intake zone 1130 and aparticle inspection zone 1140. The cartridge body 1110 includes agear-shaft hole 1150 that will be discussed further below. In alternateembodiments, particularly in cases where it is desired to be able torewind as well as advance the tape, there may be a second gear-shafthole (not shown).

FIGS. 12 and 13 show a cross-section of the cartridge body with themedia (FIG. 13) and without the media (FIG. 12). The cross-section isfor a plane parallel to, in the middle of, planes corresponding to frontpanel 1111 (FIG. 11) and back panel 1112 (FIG. 11). The dashed lines inFIGS. 12 and 13 represent portions of the plan-view edges of front panel1111 and back panel 1112 shown in FIG. 11.

Referring now to FIG. 13, a supply reel 1380 of adhesive coated tape1370 is mounted to supply-reel post 1260 (FIG. 12). In the air-intakezone 1130, the tape guide structure 1120 both fixes the location of theadhesive coated tape 1370 where it collects particles in the face of airpressure from air entering the cylindrical housing 1010 (FIG. 10) viathe air-intake slot 1030 (FIG. 10). The adhesive coated tape 1370 thenpasses the particle inspection zone 1140 and is finally collected at theuptake reel 1390. Optionally, after use within the particle collectiondevice 1000, the particle-media cartridge may be removed from device1000 and sent to a laboratory where particles captured by media can befurther studied optically or with bio-assays. Such a particle-mediacartridge physically containing captured airborne particles is oneembodiment of physical archive 260 of FIG. 2.

Referring now to FIG. 11, in a specific embodiment, a user-removable orreplaceable particle media cartridge is provided. The cartridge includesa front panel 1111, a back panel 1112, opposite the front panel. Sidepanels including a top side panel 1113A, a bottom side panel 1113B, aleft side panel 1113C, and a right side panel 1113D extend between thefront and back panels. The top and bottom side panels are opposite toeach other. The left and right side panels are opposite to each other.The top and bottom side panels are orthogonal to the right and left sidepanels. As shown for left, top and right sides, side “panels” may coveronly a small portion of their respective side. The cartridge has a shapeof a rectangle.

Referring now to FIG. 13, the right side panel includes a first openingor slot that may be referred to as air intake zone 1130. The top sidepanel includes a second opening or slot that may be referred to asparticle inspection zone 1140. The left side panel includes a thirdopening or slot that may be referred to as an exhaust port 1379. Alength of the cartridge between the top and bottom side panels is L1, awidth of the cartridge between the left and right side panels is W1, alength of the air intake zone opening is L2, a length of the particleinspection zone opening is L3, and a length of the exhaust opening isL4. In an embodiment, a ratio of L2 to L1 may be about 1:1.5, but mayvary greatly such as 1:1.3, 1:1.4, 1:1.6, or 1:1.7. A ratio of L3 to W1may be about 1:1.4, but may vary greatly such as 1:1.2, 1:1.3, 1:1.5, or1:1.6. A ratio of L4 to L1 may be about 1:1.5, but may vary greatly suchas 1:1.3, 1:1.4, 1:1.6, or 1:1.7.

A thickness of the cartridge between the front and back panels is T1. Awidth of the air intake zone opening is W2. A width of the particleinspection zone opening is W3. A width of the exhaust opening is W4. Inan embodiment, the width of the openings W2, W3, and W4 are equal. Inanother embodiment, a width may be different from another width. In anembodiment, a ratio of at least one of W2, W3, or W4 to T1 is about1:1.4, but may vary greatly such as 1:1.2, 1:1.3, 1:1.5, or 1:1.6. Ashape of the intake zone, particle inspection zone, and exhaust openingsmay be a rectangle or other shape (e.g., oval, round, obround, orcircle).

Inside the cartridge is supply reel 1380, uptake reel 1390, and tapeguide structure 1120. The supply reel includes the roll of tape. Thetape includes an inside or bottom surface 1381A and an outside or topsurface 1381B, opposite the inside surface. The tape is wound so thatthe inside surface faces towards a center of the roll, and the outsidesurface faces away from the center of the roll. The outside surface ofthe tape includes an adhesive. The tape may be made of a thin flexiblematerial such as narrow strip of plastic. In an embodiment, the tape isnon-magnetic or not magnetic or does not include a magnetizable coating.The tape includes an adhesive coating on the outside surface of the tapeto trap particles. In some embodiments, tape may be clear, translucent,transparent, or at least partially transparent to facilitateillumination of trapped particles. That is, the tape may be made of amaterial that allows at least some light to pass through.

The inside surface of the tape may not include the adhesive andpreferably moves with minimal or low friction against tape guide 1120.The inside surface may be treated with a coating that allows the insidesurface of the tape to glide freely across the tape guide. For example,in an embodiment there is a roll of tape including an inside surface andan outside surface. A coating or treatment is applied to the insidesurface such that a coefficient of friction of the inside surface afterthe treatment is less than a coefficient of friction of the insidesurface before the treatment. In another specific embodiment, the tapeor portions of the tape may include a magnetizable coating. Such amagnetizable coating may be used to mark and read locations along thelength of the tape of interesting particles that may merit laterlaboratory testing such as bio-assays.

The tape guide structure is sandwiched between the first and secondpanels of the cartridge. The tape guide includes a first segment 1382A,a second segment 1382B, orthogonal to the first segment, and a thirdsegment 1382C extending between ends of the first and second segment.The first segment extends in a direction parallel to the right sidepanel. The first segment extends along at least a portion of the lengthof the front and back panels. The first segment includes a surface thatfaces the first opening (e.g., air intake zone) of the cartridge.

The second segment extends in a direction parallel to the top sidesurface. The second segment extends along at least a portion of thewidth of the front and back panels. The second segment includes asurface that faces the second opening (e.g., particle inspection zone).A length of the first segment may be greater than a length of the secondsegment. A length of the first segment may be less than a length of thesecond segment. A length of the first segment may be the same as alength of the second segment.

The tape extends from the supply reel, across the top surfaces of thefirst, second, and third segments of the tape guide structure, andterminates at the uptake reel. The uptake reel is closer to the top sideof the cartridge than the supply reel. The supply reel is closer to thebottom side of the cartridge than the uptake reel. The tape isconfigured so that the inside surface contacts the top surfaces of thefirst, second, and third segments of the tape guide structure while theoutside surface of the tape, which includes the adhesive, is exposed atthe air intake and particle inspection zones. Thus, particles enteringthe air intake zone can be trapped by the adhesive and then inspected atthe particle inspection zone. The air can pass from the air intake zoneand out the exhaust port of the cartridge. The inside surface of thetape may be smooth or without the adhesive so that the tape can glideacross the tape guide structure.

The first segment of the guide is positioned so that it is slightlyrecessed within the opening of air intake zone 1130. That is, right sideedges 1306 of the front and back panels of the cartridge extend slightlypast the first segment. A distance from the right side edges of thepanels to the first segment may be at least a thickness of the tape. Therecessing of the first segment helps to protect the tape from unintendedcontact with other objects.

Similarly, the second segment of the guide is positioned so that it isslightly recessed within the opening of particle inspection zone 1140.That is, top side edges 1308 of the front and back panels of thecartridge extend slightly past the second segment. A distance from thetop side edges of the panels to the second segment may be at least athickness of the tape. The recessing of the second segment helps toprotect the tape from unintended contact with other objects.

In the example of the cartridge shown in FIG. 13, the first and secondsegments of the tape guide are on adjacent sides of the cartridge. Thatis the first segment is on the right side of the cartridge and thesecond segment is on the top side of the cartridge. The position of thetape guide segments corresponds to the design of the particle monitor.For example, when the cartridge is inserted into the particle monitor,the second segment of the tape guide will be located directly below theoptical subsystem or microscope including camera sensor and lensassembly. It should be appreciated, however, that the tape guidesegments may be positioned at other locations depending upon the designof the particle monitor.

An angle 1314 is between the second and third segments. An angle 1316 isbetween the first and third segments. In an embodiment, the angles areobtuse, i.e., the angles are more than 90 degrees but less than 180degrees. The angles and positioning of the tape guide segments help toprevent creases in the tape as the tape transitions from the supplyreel, to the intake zone, below and past an upper right corner 1318 ofthe cartridge, to the inspection zone, and to the uptake reel. The endsand corners of the tape guide may be rounded as shown in the figure tohelp ensure that the tape glides smoothly over the tape guide and doesnot snag.

The cartridge, including the tape guide structure, may be made ofplastic, nylon, metal, or other material, or combination of materials.The tape guide structure may be formed or molded as a single unit withone of the front or back panels of the cartridge. Alternatively, thetape guide structure may be formed as a unit separate from the front andback panels. When the tape guide structure is formed as a separate unit,the tape guide structure may be attached to at least one of the front orback panels using any number of a variety of techniques. Such techniquesmay include snap-fits, fasteners (e.g., screws), glues, and others.

Likewise, the front and back panels may be fastened together using anynumber of a variety of techniques. For example, the front and backpanels may be snap-fitted together. The front and back panels may beglued together. In an embodiment, the front and back panels areconnected using screws. In this embodiment, each corner of one of thefront or back panel may include a screw boss. The boss provides amounting structure to receive a screw. The screw passes through a holein a corner of one of the front or back panels and is received by ascrew boss located in a corresponding corner of another of the front orback panels.

FIG. 14 shows a plan-view of selected items of the particle collectiondevice 1000 shown in FIG. 10. The device includes two electric motors.Orientation motor 1410 rotates the cylindrical housing 1010 and itscontents about its vertical axis and relative to the base 1020 (FIG.10). While the orientation motor 1410 is not centered with respect tothe axis of the cylindrical housing 1010, the orientation motor's gearshaft 1420 is centered. The intake-reel gear shaft 1440 of thecartridge-reel motor 1430 extends horizontally and controls the rotationof the uptake-reel 1390 (FIG. 13) of the cartridge. The gear shaft hole1150 (FIG. 12) allows the intake-reel gear shaft 1440 to enter theparticle-media cartridge body 1110 (FIG. 11). Many of the contentscontained within the cylindrical housing 1010, including motors 1410 and1430, are mechanically supported by the internal mounting structure1450. For example, internal components of the monitoring device such aprinted circuit board, motors, and so forth may be attached to theinternal mounting structure using various fasteners, welding, adhesives,or combinations of these. Examples of fasteners include nuts, bolts,screws, and washers. Adhesives include epoxy or glue. Examples ofwelding include plastic welding. The internal mounting structure 1450may be formed of a sculpted volume of plastic. The mounting structuremay be formed using injection molding.

FIG. 15 shows a vertical cross section of particle monitor device 105according to a specific embodiment. In this specific embodiment, theparticle collection device includes three electronic boards. There is amotherboard 1510, an orientation-motor circuit board 1530, and acartridge reel motor circuit board 1540.

Motherboard 1510 contains many electronic components including amicroprocessor (e.g., Raspberry Pi) and a wifi antenna 1520.Alternatively Bluetooth or any other wireless protocol may instead oradditionally be used. For effective wireless communication, it ispreferable that cylindrical housing 1010 be constructed from anon-conductive material such as plastic rather than a metal.

Additional circuit boards (not shown) may be included. Also not shown inFIG. 15 for purposes of clarity are numerous wires interconnectingvarious components such as wires between the motors and theircorresponding circuit boards. Motherboard 1510 may contain the hardwareof local processor 240 of FIG. 2.

The motors are located closer to a bottom of the particle monitor than atop of the particle monitor. Motors can be relatively heavy. Locatingthe motors towards the bottom of the particle monitor helps to lower thecenter of gravity and provide stability so that the monitor is unlikelyto tip over. Likewise, a power supply such as a battery may be locatedcloser to the bottom of the monitor than the top of the monitor.

Specifically, with respect to a vertical positioning, the orientationmotor is between the bottom of the monitor and the motherboard. Thecartridge reel motor is between the orientation motor and the camerasensor. The camera sensor, being relatively light, is positioned closerto the top of the monitor than the bottom of the monitor. The camerasensor is between the cartridge reel motor and the top of the particlemonitor. With respect to a horizontal positioning, the cartridge reelmotor is between the motherboard and the cartridge door.

FIG. 16 illustrates how sampled ambient air flows through the monitordevice 1000. Sampled ambient air 1620 enters through the air-intake slot1030 and immediately encounters the air-intake zone 1130 (FIG. 13) ofthe particle-media cartridge. Here the adhesive-coated tape 1370 (FIG.13) captures many of the particles within the sampled ambient air 1620.Device-interior air 1630 then exits out the back side of theparticle-media cartridge body 1110 (FIG. 11); for this purpose and asseen in FIG. 13, the back side of the cartridge is open rather thanclosed. Finally exhaust air 1640 (FIG. 16) leaves the device. Thisairflow is driven by blower 1610 which pushes out exhaust air 1640 andsucks in sampled ambient air 1620. The blower is opposite the air intakeslot and above the exhaust. A gap 1617 between a bottom of the housingand a top of the base allows the exhaust air to escape. The mechanismsfor ambient air sampling illustrated in FIG. 16 represents oneembodiment of air intake hardware 220 of FIG. 2.

Air intake slot 1030 is opposite the blower and is configured to directa flow path of ambient air created by the blower towards or over thefirst opening of the cartridge or air intake zone. For example, therecan be channel, duct, conduit, tube, or passageway that directs the flowpath of the air from the air intake zone. Particles, such as pollen,mold spores, or both, in the air are trapped by the adhesive on thetape. Preferably, the airflow in the air intake zone is turbulent inorder to maximize or increase the chances that particles in the sampledair will be separated from the air and adhered to the capturing medium.When desired, cartridge reel motor 1430 (FIG. 14) advances the tapecontaining the trapped particles to the second opening of the cartridgeor inspection zone. The camera sensor can then capture images of theparticles trapped within the adhesive tape.

FIG. 17 shows a side view of an inside portion of monitor device 1000.The monitor device includes an optical subsystem 1705, illuminationsubsystem 1710, cartridge well 1715, platform 1733, and particle-mediacartridge 1105. FIG. 17 illustrates a loaded particle-media cartridge inthe cartridge well along with an optical subsystem for particleinspection. FIG. 18 provides more detail on the optical and illuminationsubsystems. During a collection period, particles entering the monitorare trapped within air intake zone 1130 by the adhesive of the tape. Thetape or, more specifically, a portion of the tape having the trappedparticles, is then advanced to particle inspection zone 1140 forinspection. The duration of the collection period can be configured by auser or administrative user. For example, the collection period may beconfigured to be 5, 10, 15, 20, 30, 60, 90, 120, or more than 120seconds (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 15, 30, 45, or more than 45minutes; 1, 2, 3, 4, 5, or more than 5 hours). The collection period maybe less than 5 seconds.

The optical subsystem includes a camera sensor 1720, lens assembly 1725,and tube 1730. The lens assembly is positioned at a bottom end of thetube and the camera sensor is positioned at a top end of the tube,opposite the bottom end of the tube. The cartridge well receives andholds the particle-media cartridge in a vertical position.

Platform 1733 is positioned above the cartridge well. The platform canbe between the cartridge well and illumination and optical subsystems.The platform includes a first hole 1735, a second hole 1745, and a thirdhole 1740. The bottom end of the tube of the optical subsystem extendsinto the first hole which opens to face particle inspection zone 1140 ofthe particle media-cartridge. In other words, when the particlemedia-cartridge is inserted into the particle monitor, the particleinspection zone of the cartridge aligns with the first hole. The camerasensor is directly above the lens assembly which is directly above theparticle inspection zone. The arrangement allows the camera sensor tocapture images of particles that have been trapped by the adhesivecoated tape.

In other words, in the example shown in FIG. 17, the platform is abovethe cartridge well that receives the collection cartridge. The camerasensor is positioned within the particle monitor device to be above orover the second opening or particle inspection zone of the cartridge.The camera sensor is closer to a top of the particle monitor than thecartridge.

Positioning the camera sensor above the particle inspection zone helpsto reduce the probability of particles falling onto the camera lens andobscuring the images. For example, in some cases, the bond between theadhesive coated tape and collected airborne particles may be weak, theadhesive coated tape may include a large collection or mound ofparticles and particles at the top of the mound may not be secured tothe adhesive coated tape, and so forth. The collection cartridge andcamera sensor may be aligned such that a line passing through the supplyand uptake reels passes through the particle inspection zone and lens tothe camera sensor.

In a specific embodiment, the cartridge well is rotatable about avertical axis parallel to the central axis passing longitudinallythrough the housing. For example, at least one of the top, bottom, orside of the cartridge well may be connected to a pin (e.g., rod,spindle, shaft, or axle). The pin may sit or revolve within a hole,bushing, or ball bearing connected to the housing. In this specificembodiment, when the media cartridge is loaded through the cartridgedoor and into the monitor, the cartridge well can pivot so that theair-intake slot of the housing aligns with or faces the air intake zoneof the cartridge. This helps to facilitate airflow towards the airintake zone of the cartridge.

In an embodiment, the cartridge well pivots through a distance at leasta thickness of the cartridge. The cartridge well may pivot through anynumber of degrees (e.g., 1, 2, 3, 4, 5, 10, 15, 20, 30, 60, 90, 120, or180 degrees). The ability of the cartridge well to pivot allows theair-intake slot to be located anywhere on the housing. For example, theair-intake slot may be located on an opposite side of the cartridgedoor. In other words, a distance between the air-intake slot and thecartridge door may be equal to a diameter of the housing or half thecircumference of the housing.

Rotating the cartridge away from the cartridge door helps to ensure thatambient or outside light that may enter or leak through the cartridgedoor and into the interior space of the monitor does not enter theparticle inspection zone when the trapped particles are beingilluminated by the illumination subsystem. Reducing or minimizing theamount of ambient or outside light entering the particle inspection zonehelps to ensure accurate measurements.

In a specific embodiment, the illumination and optical subsystems remainstationary or are fixed-in-place while the cartridge well pivots. Thishelps to ensure consistent measurements. In another specific embodiment,one or more of the illumination or optical subsystems may pivot with orwith respect to the cartridge well.

The cartridge well may pivot through any number of positions. Forexample, there can be a first position in which the cartridge well facesthe cartridge door so that the cartridge can be loaded into the well.The cartridge well may then pivot from the first position to a secondposition where the air intake zone of the cartridge faces the air intakeslot of the housing. The cartridge well may remain in the secondposition while the collected particles are illuminated and particleimages captured. The cartridge well can then pivot from the secondposition back to the first position so that the cartridge can be removedand another cartridge inserted.

In another specific embodiment, there can be a first position in whichthe cartridge well faces the cartridge door so that the cartridge can beloaded into the well. The cartridge well may then pivot from the firstposition to a second position where the air intake zone of the cartridgefaces the air intake slot of the housing. Once a collection period hasended, the cartridge well may pivot from the second position to a thirdposition, away from the air intake slot, where the collected particlesare illuminated and particle images captured. The cartridge well canthen pivot from the third position back to the second position foranother particle collection session, or pivot back to the first positionso that the cartridge can be removed and another cartridge inserted.

In other embodiments, the cartridge well may be designed to translate.For example, in another specific embodiment, a particle monitor mayinclude a tray that slides out of the particle monitor. The trayreceives the cartridge and slides back into the particle monitor. In theexample shown in FIG. 10, the cartridge door is shown as being on a sideof the particle monitor between the top and bottom of the monitor. Theside entry helps to facilitate a short overall height and small diameterof the monitor.

In other embodiments, however, the cartridge door may be located on thebottom of the monitor and the cartridge may be inserted through thebottom of the monitor. Locating the cartridge door on the bottom helpsto reduce the probability of unwanted water (e.g., rain) or other debrisentering into the monitor. The cartridge door may be located on the topof the monitor and the cartridge may be inserted through the top of themonitor. Locating the cartridge door at the top can allow a cartridge tobe loaded and removed without having to pick-up the monitor.

As shown in FIG. 17, the optical subsystem is slightly offset towards aright side of the platform. The optical subsystem is closer to the rightside of the platform than a left side of the platform, opposite theright side. The optical subsystem may be closer to a side of thecylindrical housing than a central axis passing longitudinally throughthe cylindrical housing. This offsetting or arrangement of the opticalsystem helps to facilitate the compact design of the particle monitordevice as other internal components may be located to the left of theoptical tube. Also, to better approximate real-time monitoring, such anoffset also has the benefit of reducing the distance between theparticle capture at air intake zone 1130 and particle inspection zone1140. In another specific embodiment, the optical axis may be symmetricwith respect to the light sources.

The second hole 1745 houses a first illumination or light source 1750.Light from a first light emitting element 1824 (FIG. 18) is directedwithin a guide 1826 to a diffuser 1825. The third hole 1740 houses asecond illumination or light source 1755. The illumination sourcesilluminate the particle inspection zone so that the camera sensor cancapture images of the trapped particles when illuminated by theillumination sources.

For example, FIG. 18 shows an enlarged view of a portion of the sectionview shown in FIG. 17. Particles 1830 collected on the tape have beenmoved to particle inspection zone 1140. First light source 1750illuminates 1803 the particle inspection zone with first light. Camerasensor 1720 (FIG. 17) captures images of particles in particleinspection zone 1140 (or a scene) within a field view of the camerasensor to generate a first image. That is, the first image is generatedwhile the particles are illuminated with the first light. Second lightsource 1755 illuminates the particle inspection zone with second light,different from the first light. The camera sensor captures particles inthe particle inspection zone within the field view of the camera sensorto generate a second image. That is, the second image is generated whilethe particles are illuminated with the second light.

In an embodiment, it is desirable that the area around the particleinspection zone be dark. This helps to provide a controlled lightingenvironment for illuminating the particles under different specifiedlighting conditions and image capture. Thus, components within the areaaround the particle inspection zone may be black, colored black (e.g.,painted black or a dark color), non-reflective, processed so that theresulting surface finish is darker as compared to the surface before theprocessing, and so forth.

The first and second lights have different spectral characteristics. Forexample, the first light may include white light (e.g., light having abroad range of wavelengths and is perceived by the human eye as beingcolorless) and the second light may include light corresponding to anabsorption spectrum of a particle of interest. In an embodiment, thefirst and second images are analyzed to identify or discriminate theparticles. For example, the first and second images may be compared toeach other to detect changes or differences in the appearance of theparticles in the images based on the different lighting conditions underwhich the particles were photographed.

Detecting such changes (or the lack of changes) can provide anindication of what a particle might be (or not be) because differenttypes of particles can have different light absorption characteristics.These differences in light absorption characteristics can be exploitedin order to identify or discriminate the particles. Capturing variousimages of the same particles but under various different lightingconditions can be used to “probe” and identify or discriminate theparticles.

As discussed, lens assembly 1725 images the particles within particleinspection zone 1140 on camera sensor 1720 (FIG. 17). The lens assemblymay include one or more lenses. FIG. 18 illustrates the case where thelens assembly includes a weak (i.e., longer focal length) lens 1812 incombination with a strong (i.e., shorter focal length) lens 1814. In theexample shown in FIG. 18, the strong lens is closer to the particleinspection zone than the weak lens. Optionally, the lens assembly 1725may provide an electrically controlled focal length, for example,through a combination of a strong lens 1814 of fixed focal length and aweak lens 1812 whose focal length is electrically controlled.

Given a fixed location of camera sensor 1720 and of lens assembly 1725,increasing the net or effective focal length of the lens assembly 1725moves the object focal plane down and decreasing the focal length movesthe object focal plane up. That is by properly adjusting the focallength of the lens array 1725, one can bring into focus particles 1830.Furthermore, for larger particles or for optical arrangements withshallower depths of field, different adjustments of net focal length ofthe lens assembly 1725 can bring into focus different horizontal layersof a translucent particle like pollen grains. A set of images focused ondifferent horizontal layers may provide information on thethree-dimensional structure.

A lens with an electrically controlled focal length is generally morereliable than a moving mechanical mechanism. In other words, thereliability of modern electronic devices depends heavily in replacingmoving mechanical mechanism with electronic mechanisms. From thisperspective, it is very attractive to be able to be able to adjust inreal-time the focus of the particle monitor's optical system with no orfew mechanical movements, but instead control the focal length of thelens assembly purely electronically. Available lenses withelectronically controller focusing tend to be weak lenses, too weak foridentifying or discriminating particles. A weak lens in combination witha strong lens, however, can provide for reliability identifying ordiscriminating particles. In other words, this problem can be overcomewith a strongly focusing lens assembly comprising a fixed strong lensand a weak electronically controlled lens.

In any case, an optical axis 1815 of the lens array intersects theparticle inspection zone 1140 where particles 1830 such as pollen grainsmay be located. Such a lens assembly may be part of image capturehardware 226 of FIG. 2.

The camera sensor 1720 (FIG. 17) may be a black-and-white camera sensor,but in order to generate richer spectral information it is preferablethat the camera sensor 1720 be color sensitive such as providing theability to capture RGB (red-green-blue) color images. Indeed, the largevolume or scale at which color camera sensors are manufactured ascompared to black-and-white camera sensors have resulted in color camerasensors being less expensive than black-and-white camera sensors.

Both black-and-white cameras and color cameras provide information onthe shape and structure of imaged objects, in other words the“morphology” of imaged objects. Color cameras also provide colorinformation. The particle monitor can analyze an image to distinguishbetween types of particles through morphological features (e.g., is itround or rod like?, is it smooth or spikey?, is it large or small?, andso forth).

In another specific embodiment, the camera sensor 1720 may be alight-field camera sensor. These items represent embodiments of theimage capture hardware 226 of FIG. 2.

Referring back now to FIG. 18, third hole 1740 within platform 1733houses second illumination source 1755. The second illumination sourceincludes a second light emitting element 1840, a quantum-dot film 1855,an optional diffuser 1850, and an optical shaft 1860. Second hole 1745within the platform houses first illumination source 1750. A diffusercan be optional as the quantum-dots themselves will randomize thedirections of emitted light.

Second light emitting element 1840 provides light reaching the particleinspection zone 1140 via light propagation approximately parallel to anillumination axis 1845. The illumination light may be visible light, UVlight, or infrared light, or a combination thereof. As discussed,different types of particles can have different light absorptioncharacteristics. For morphology analysis, visible light, or even onecolor of visible light can be sufficient. However, in some cases, amorphology analysis will not be sufficient to make a conclusiveidentification as there can be particles of different types but whichhave the same or similar geometric features. Color information becomesparticularly interesting when it provides even a crude level ofbiochemical analysis without the delays and cost of wet-laboratorytechniques. The differences in light absorption characteristics ofdifferent particles can be exploited to identify particles ordiscriminate between particles.

For example, pollen grains tend to have a yellowish color, so color asperceived by the human eye, or an RGB camera sensor under white lightillumination is of value to check if a candidate pollen grain is indeedyellowish. Illuminating with white light and capturing the resultingscene provides a useful indication of the colors of the particles thathave been captured. Grass pollens tend to have bio-moleculechlorophyll-a and hence a pollen grain with visible light absorptionpeaks of chlorophyll-a is likely to be a grass pollen.

Fluorescence under UV illumination is a marker of bio-molecules that canbe used to distinguish between organic and inorganic particles.Biochemcial information can be provided by UV fluorescence. Fluorescenceis a property some molecules have in which they absorb light of onecolor and emit light of a different color (e.g., different wavelength).While UV light might not be detected by the camera sensor, the resultingfluoresced or emitted light from the particle may be detected by thecamera sensor. As another example, illumination in near infra-red (nearenough in wavelength to visible light to be detected by the camerasensor) may provide useful information in regards to identifyingparticles or discriminating between particles.

Camera sensor 1720 (FIG. 17) may image scattered light, fluorescentlight, or both. Light scattering, where photons bounce off objects in adifferent direction without changing their wavelength/color is theworkhorse of light imaging. With rare exceptions, this is how we seeobjects in our daily lives when we use our eyes. Just as with our humaneyes, in the particle monitor's basic object shape and color informationcomes from light scattering. UV fluorescence is less common (such as in“black lights”) and is of interest in particle identification anddiscrimination because UV fluorescence indicates the presence ofbiological materials and may provide information about the types ofbiological materials.

Optionally, to provide a more uniform illumination of the particleinspection zone 1140, a diffuser 1850 may be placed along theillumination axis between second light emitting element 1840 and theparticle inspection zone 1140. The second light emitting element 1840and the diffuser 1850 may be mechanically connected with an opticalshaft 1860 forming a rigid illumination-source sub-assembly.

Preferably, optical shaft 1860 has optical wave-guiding properties so asto more efficiently direct light from second light emitting element 1840to particle inspection zone 1140. Third hole or illumination channel1740 may penetrate platform 1733 in order to hold the rigidillumination-source sub-assembly in place and to remove material aroundthe illumination axis 1845.

As shown in the example of FIG. 18, there is a 55-degree angle betweenthe optical axis 1815 and the illumination axis 1845; however otherangles are also possible. This includes angles larger than 90-degrees ifthe adhesive-coated tape and the tape guide 1120 under the particleinspection zone 1140 are at least partially transparent. Larger than90-degree illumination angles are also an option for alternateembodiments for which sampled particles are captured on transparentglass or plastic slides instead of with adhesive-coated tape. FIG. 18illustrates just one possible azimuthal angle for an illumination axis1845; optionally any azimuthal angle may be used. Such illuminationoptions represent embodiments of illumination hardware 224 of FIG. 2.

Light emitting element 1840 may be an LED (light emitting diode)including possibility an OLED (organic light emitting diode), or alaser, or any other type of light generating device. Furthermore, lightemitting element 1840 may be of the downstream end of an optical fiberbringing light from a light emitting element mounted elsewhere. Lightemitting element 1840 may provide a wide range of wavelengths, such aswith a white-LED, or provide a narrow range of wavelengths, such as witha laser. To provide more information for recognition of particle types,there can be multiple illumination sources.

The holes formed in the platform for light sources, optical shaft, orboth may have a cross-sectional shape of a circle. In other embodiments,the cross-sectional shape of a hole may be an oval, square, rectangle,or other shape. In some applications it may be useful to usecross-sectional hole shape as part of a keying system that controls whattype of illumination source sub-assemblies are inserted into whichholes. A light source may include a light emitting element and opticalfiber. The use of optical fiber allows the light emitting element to belocated anywhere within the particle monitor and not necessarily withinthe platform. The ability to locate the light emitting element anywherewithin the particle monitor helps to facilitate a compact design.

For example, the light emitting element may be located in the base ofthe platform. An end of an optical fiber may be connected to the lightemitting element. An opposite end of the optical fiber may be connectedto a hole or opening in the platform. The optical fiber transmits lightfrom the light emitting element to the platform or particle inspectionzone so that the collected particles can be illuminated for the camerasensor. There can be multiple strands of optical fiber. Across-sectional shape of the optical fiber may be a circle or othershape.

As previously stated, image capture hardware 226 of FIG. 2 mayadvantageously take advantage of commercially available camera sensors.Due to mass market demand for color digital cameras including camerasbuilt into smart phones, sophisticated RGB (red, green, blue) camerasensors are available at relatively low cost. A feature of the systemallows for the use of such relatively low-cost camera sensors for anautomated pollen detection systems based on optical imaging of sampledpollen. Pollen color information is of interest for differentiationbetween types of pollen and other allergens as well as differentiationbetween allergens and background non-allergenic particulates. Now let ustake a closer look at the spectral characteristics mass produced camerasensors.

FIG. 19 illustrates spectral characteristics typical of an RGB camerasensor such as may be found in consumer-level digital cameras.Horizontal axis 1910 represents optical wavelengths within the visiblespectrum from violet at the left to red at the right. Vertical axis 1920represents the quantum efficiency (percentage of photons resulting inone electron of current) of a camera sensor sub-pixel. Thedot-dot-dashed curve 1930 represents the spectral response of red or “R”sub-pixels of an RGB camera sensor. The dot-dashed curve 1940 representsthe spectral response of green or “G” sub-pixels of an RGB camerasensor. The dashed curve 1950 represents the represents the spectralresponse of blue or “B” sub-pixels of an RGB camera sensor.

These spectral responses are determined in large part by color filtersplaced in front of sub-pixels as part of the construction of the camerasensor. Often, the color filters include more green elements as comparedto red or blue elements. This is because the human visual system peaksin sensitivity in the green spectral region (e.g., peaks atapproximately 550 nm wavelength). Thus, the abundance of green sensorpixels in the imaging device allows for approximating the color responseof the human visual system.

As can be seen, the spectral response curves are quite broad andoverlapping. For conventional digital camera purposes, this has theadvantage that there is no visible light wavelength for which a colordigital camera is blind. However, from the perspective of quantitativespectral analysis, the broad and overlapping spectral characteristics isa disadvantage because the absorption characteristics of particles ofinterest (e.g., grass pollen) may be much more narrow. Thus, in somecases, it can be very difficult to distinguish and discriminatedifferent particle types based on color using a broad and overlappingemission spectra to illuminate the particles.

A close look at the spectral profiles in FIG. 19 reveals a significantamount of what may be described as “color crosstalk.” For example, evenred light at a wavelength of 700 nm will not only excite red RGB pixelswith a quantum efficiency of about 35 percent, but also excite “green”RBG pixels with a quantum efficiency of order 10 percent and excite“blue” RGB pixels with a quantum efficiency of order 5 percent. It is anover-simplification to say that “red” RGB pixels detect “red” light,“green” RGB pixels detect “green” light and “blue” RGB pixels detect“blue” light. For a deeper appreciation of the system discussed herein,and in particular various embodiments of the illumination hardware 224(FIG. 2) presented further below, it is useful to keep this fact inmind.

In conventional applications of RGB camera sensors, such as in colordigital cameras, color digital microscopes, and so forth, it is takenfor granted that associated lens assemblies must be achromatic so thatthe red, green and blue sub-pixel images are all brought to an equallysharp focus. RGB camera sensors are conventionally associated withachromatic optics. The requirement that RGB camera optics be achromaticadds to the complexity of the optics, and hence its cost, particularlyif a relatively large aperture is required.

Applicants have appreciated, however, the advantages provided by quantumdots for a particle (e.g., pollen or mold spore) imaging system. Atpresent, from a commercial perspective, quantum dots are a new andunconventional technology. With the recent development of quantum dotfilms for use in backlight systems of liquid crystal displays (LCDs),only recently have quantum dots started to go beyond the research laband become a significant commercial technology. One example of a companydeveloping quantum dots is Nanosys of Milpitas, Calif.(www.nanosysinc.com). As mass production of quantum dots ramps up, it isreasonable to assume that there will be dramatic cost reductions forquantum-dot based illumination sources, such as quantum-dot enhanced LEDlight sources.

Quantum dots are very small particles of semiconductor materials thatare only a few nanometers in diameter. This small size affects the bandgap energy, and hence light emission wavelength, of the quantum dot. Byadjusting the quantum dot diameter during its manufacture, thewavelength of its emitted light may be tuned. A quantum dot (QD) is ananocrystal made of semiconductor materials that is small enough toexhibit quantum mechanical properties. Different sized quantum dots emitdifferent color light due to quantum confinement.

In other words, electronic characteristics of a quantum dot are closelyrelated to its size and shape. For example, the band gap in a quantumdot which determines the frequency range of emitted light is inverselyrelated to its size. In fluorescent dye applications the frequency ofemitted light increases as the size of the quantum dot decreases.Consequently, the color of emitted light shifts from red to blue whenthe size of the quantum dot is made smaller. This allows the excitationand emission of quantum dots to be highly tunable. Since the size of aquantum dot may be set when it is made, its electronic and opticalproperties may be carefully controlled. Quantum dot assembliesconsisting of many different sizes, such as gradient multi-layernanofilms, can be made to exhibit a range of desirable emissionproperties.

Specifically, as schematically illustrated in FIG. 20, its smalldimensions affect its band gap. FIG. 20 shows quantum dots 2030, 2032,and 2034 in varying sizes. There are incoming photons of light 2040 intothe quantum dots and outgoing photons of light 2050 from the quantumdots. The vertical direction 2010 in FIG. 20 represents electron energy(e.g., a vertical electron energy axis). The horizontal dotted, dashedand solid lines 2024 a-b, 2022 a-b, and 2020 a-b, respectively,represent the band gap limits of quantum dots of small, smaller and evensmaller diameters respectively.

The lower sets of horizontal lines represent the top of the valence bandand the upper sets of horizontal lines represent the bottom of theconduction band. A photon of light may be absorbed if its energy exceedsthe band gap energy, that is, if its wavelength λ_(IN) is sufficientlyshort. When such a photon is absorbed, a electron e⁻ previously in thevalence band is excited into the conduction band, leaving a hole h⁺ inthe valence band. This is illustrated to the left of FIG. 20.

The resulting electron e⁻ and hole h⁺ quickly loose energy until theyare at the bottom of the conduction band and at the top of the valenceband, and then the electron e⁻ at the bottom of the conduction band willemit a photon of wavelength λ_(OUT) loosing sufficient energy to occupythe hole⁺ in the valance band. This is illustrated to the right of FIG.20 for the case of the smallest of the three quantum-dot diametersconsidered in the figure. The wavelength λ_(OUT) of the lower energyre-emitted photon is longer than the wavelength of the higher energyabsorbed photon λ_(IN).

Such a process of photon absorption at a shorter wavelength followed bythe emission of a photon at a longer wavelength is an example offluorescence. The mechanisms illustrated in FIG. 20 may be summarized bysaying quantum dots fluoresce at wavelength λ_(OUT) when excited bylight of a shorter wavelength λ_(IN). A key observation is that whilequantum dots may absorb photons of a broad range of wavelengthscorresponding to any photon energy exceeding the band gap, the emittedor fluorescent photons are approximately monochromatic with a wavelengthcorresponding to the band gap energy. A desired emitted wavelengthλ_(OUT) may be provided by appropriately tuning the diameter of thequantum dots during their manufacture.

The ability to fabricate quantum dots corresponding to any desired coloror wavelength has been well demonstrated. In a specific embodiment, aparticle monitor includes “size-tuned quantum dots.” In this specificembodiment, the emission wavelength is mainly tuned via manufacturingcontrol of particle size.

In another specific embodiment, a particle monitor includes“composition-tuned quantum dots.” In this specific embodiment, theemission wavelength is mainly tuned via manufacturing control of theparticle composition (e.g., adjusting the material composition in orderto control the quantum-dot emission wavelength). Composition-tunedquantum dots may be composed of a mixture of CsPbI₃, CsPbCl₃ and CsPbBr₃where (referring to the periodic table) Cs is cesium, Pb is lead, I isiodine, Cl is chlorine and Br is bromine. By mixing these threecompounds in different proportions, the nanoparticle's bandage and henceemission wavelength may be tuned.

In some cases, “composition-tuned” quantum dots can provide a narrowspectral width (“<25 nm FWHM” or less than 25 nm full width halfmaximum) because there is no requirement to precisely control the sizeof the quantum-dot particles (as their emission wavelength is controlledmore by composition than size), but instead by precisely controlling thecomposition of the quantum dots. Quantum dots may be provided for UV orinfrared wavelengths. Particle sizes (e.g., diameter) ofcomposition-tuned quantum dots may range from about 5 nm to about 50 nm.The size may be greater than 50 nm or less than 5 nm.

Quantum dots may be defined as nano-scale particles (<1 um in largestdimension) of semi-conductor material with a band gap controlled peakemission wavelength. In embodiments where an approximately monochromaticillumination is desired quantum dots with a narrow distribution of sizesmay be used. A corresponding spectral distribution is schematicallyshown in FIG. 21. FIG. 21 shows a vertical axis 2110 and a horizontalaxis 2120. The vertical axis indicates light intensity. The horizontalaxis indicates a wavelength of emitted light. The spectrum has a peakwavelength 2130 and a wavelength spread 2140. The peak wavelength can betuned by adjusting the band gap which in turn is controlled by adjustingthe quantum dot size. A narrow wavelength spectrum helps to identifyparticles such as pollen based on color.

Full-width-at-half-maximum (FWHM) spectral widths of Δλ=50 nm, and even25 nm, are presently achieved by commercial quantum dot suppliers.Narrower spectral widths may well be possible with quantum dots in thefuture. For many purposes, such as interferometry measurements, aspectral widths of Δλ=25 nm is far from monochromatic and the muchnarrower spectral widths of lasers are required.

However, fortuitously, the spectral widths that are possible fromillumination sources using quantum dots is a good match to the spectralwidths of, for example, the absorption peaks of chlorophyll-a as shownin FIG. 22. FIG. 22 shows an absorption spectrum of chlorophyll-a. Witha vertical axis 2210 representing absorption strength and a horizontalaxis 2220 for light wavelength, a curve 2230 shown in FIG. 22 representsthe absorption spectra of chlorophyll-a.

This absorption spectrum has a pronounced “chlorophyll-a red peak” 2240and a pronounced “chlorophyll-a blue peak” at 2250. In the plot abovethe two absorption peaks are centered near 665 nm and 465 nmwavelengths. As one of skill in the art would recognize, the solventsolution environment of the chlorophyll-a has a significant effect onthe locations of the peaks. Thus, depending upon factors such as thesolvent solution environment, the location of the peaks may differ suchas for chlorophyll-a on grass pollen. It should be appreciated that theprinciples of choosing quantum-dots based on the locations of the peaksremain the same.

The presence of chlorophyll-a distinguishes grass pollens from otherpollens as well as other particles, and hence a quantum-dot illuminationsource tuned to an absorption peak of chlorophyll-a is of interest inthe identification of allergenic grass pollens.

Quantum dots may be made of binary compounds (e.g., lead sulfide, leadselenide, cadmium selenide, cadmium sulfide, indium arsenide, and indiumphosphide) or ternary compounds (e.g., cadmium selenide sulfide).Quantum dots can contain as few as 100 to 100,000 atoms within thequantum dot volume, with a diameter of 10 to 50 atoms. This correspondsto about 2 to 10 nanometers.

Quantum dots absorb photons (perhaps with a broad range of wavelengths)from a light source such as an LED, and then emit photons (of a longerwavelength) with a narrow spectral spread. Alternatively, quantum dotsmay be excited electronically and serve as the original source ofphotons. For example LEDs (more specifically organic light emittingdiodes or OLEDs) may be modified so that its light originates fromelectron-hole recombination within quantum dots. Whether quantum dotsare used to create light, or to modify light, the result is light withnarrow spectral peaks.

In a specific embodiment, a method includes identifying an absorptionpeak of a particle of interest, and providing a quantum dot containingproduct having a set of quantum dots configured to correspond to theabsorption peak of the particle of interest. The quantum dot containingproduct may be a film, LED, tape, adhesive, backing material for anadhesive, or disk. The quantum dot containing product may be installedwithin a particle monitoring device.

FIG. 23 shows a conventional LED 2310 and a film 2330 containing quantumdots 2335. The film includes a matrix of transparent material in whichthe quantum dots have been dispersed throughout. The material mayinclude a clear or transparent polymer, plastic, glass, acrylic,silicone, adhesive, epoxy, or resin.

FIG. 23 illustrates the film intercepting photons of wavelength λ_(IN)2320 from the conventional light emitting diode (LED). Photons from theLED are absorbed by quantum dots that then fluoresce at a longerwavelength λ_(IN) 2340.

In a specific embodiment, the LED includes a blue LED, but can be anylight emitting element that emits a wavelength shorter than the desiredoutput wavelength. The film or other transparent medium containingquantum dots converts between input and output wavelengths via themechanisms shown in FIG. 20. A blue LED is desirable because a quantumdot can absorb a higher energy photon (of shorter wavelength) andconvert it to a photon of lower energy (of longer wavelength). Forexample, a quantum dot of a particular diameter can convert blue lightto red light because the blue light is of a higher energy than the redlight. As another example, a quantum dot of another different diametercan convert blue light to green light because the blue light is of ahigher energy than the green light. Thus, starting with a high energylight (e.g., a blue LED), increases the range of colors that can beproduced using quantum dots.

Referring back to FIG. 18, it should be appreciated that the mechanicalschematic shown in FIG. 18 of the quantum dots is merely an example ofone particular implementation of particle monitor 105. In otherimplementations, other similar and equivalent elements and functions maybe used or substituted in place of what is shown.

For example, FIG. 18 shows light emitting element 1840 (which may be aconventional LED) emitting light through quantum-dot film 1855 andoptionally through diffuser 1850. The quantum dots, however, may beintegrated with other components and give the same functionality.Specifically, rather than having a separate quantum-dot film anddiffuser, the diffuser itself may contain the quantum dots and thequantum-dot film may be omitted with the result that the color of lightilluminating the particle inspection zone 1140 is determined by thenature of the quantum dots in the diffuser and not by the color of lightgenerated by light emitting element 1840.

In another specific embodiment, a polarizer (not shown) may instead oradditionally be included along the illumination axis 1845 so that theparticle inspection zone is illuminated with polarized light. A similareffect may be obtained with greater quantum efficiency if the diffuser1850 contains quantum dots (or “quantum rods”) in the shape of elongatedellipsoids rather than spheres, and if the major axes of the elongatedellipsoids are aligned with the electric field of the desired lightpolarization. A polarizer may instead or additionally be included alongthe optical axis 1815 in order to analyze polarization of lightscattered by particles 1830. Polarized light can help to increasecontrast between the background and particles that have been collectedon the tape.

As another example, quantum dots may serve to convert electrical energyto light energy within the LED itself. More particularly, FIG. 24illustrates a direct generation of photons of wavelength λ_(OUT) 2410from a quantum-dot LED 2415. Within such an LED, the electron e⁻ andhole h⁺ to the right of FIG. 20 are provided by associated electroniccircuitry and are not the result of photon absorption. In particularelectrical current go from lead 2440 through quantum dots 2435 and tolead 2450. When an electrical current passes through quantum dots 2435,electrons combine with holes generating photons.

More particularly, FIG. 25 shows particle monitor 105 with a quantum-dotLED. The view of the particle monitor shown in FIG. 25 is similar to theview of the particle monitor shown in FIG. 18. In FIG. 25, however, alight emitting element 2540 is a quantum-dot LED and the quantum-dotcontaining film shown in FIG. 18 has been omitted. The conventional LEDshown in FIG. 18 has been replaced in FIG. 26 with a quantum-dot LED.Incorporating quantum dots within the LED itself can be more efficientthat using a film having quantum dots. For example, when light strikes afilm having quantum dots, the converted light may be emitted in anynumber of different directions (including backwards towards the lightemitting element) rather than in a direction towards the particles.Thus, incorporating quantum dots within the actual light emittingelement itself (e.g., an LED) can result in more light being directedtowards illuminating the particles. A film having quantum dots, however,might be less expensive to produce than an LED having quantum dots.

FIG. 26 shows yet another embodiment of particle monitor 105 where thequantum dots have been dispersed within an adhesive coated tape 2690 ofa collection cartridge. The view of the particle monitor shown in FIG.26 is similar to the view of the particle monitor shown in FIG. 18. InFIG. 26, however, the quantum-dot containing film shown in FIG. 18 hasbeen omitted and the quantum dots have been dispersed within theadhesive coated tape. The quantum dots may be dispersed within anadhesive of the tape, a backing material of the tape, or both.

Quantum-dots may be dispersed in the adhesive of the tape. In thisspecific embodiment, the adhesive may be clear or transparent.Alternatively, the tape may be a clear tape and the quantum dots may beplaced within a fixed supporting structure (such as dispersed within thetape guide structure of the collection cartridge or, more particularly,second segment 1382B—FIG. 13) behind or below the adhesive coated tape.In this specific embodiment, the second segment of the tape guide may bemanufactured as a unit separate from the other segments (first and thirdsegments) of the tape guide. The second segment may include a clear ortransparent matrix of material having a set of quantum dots dispersedwithin. The second segment may then be joined or connected to the thirdsegment to form the tape guide. In other words, the quantum dots may bepositioned below the collected particles. From an optics perspective,the former approach is advantageous because the quantum dots are mostimmediately behind the particles of interest. However, making quantumdots part of the adhesive coating recipe can be expensive. From a costperspective, the latter approach may be more attractive. Placement ofquantum dots may change as the cost of quantum dots drops with time.

Thus, as illustrated in FIGS. 18, 25, and 26 there can be multipledistinct ways to utilize quantum dots as a means of controlling thecolor properties of light illuminating the particle inspection zone1140. As another example, quantum dots may be dispersed within a lenscase or lamp shade of an LED.

FIG. 27 shows a top view of a platform 2705 of another specificembodiment of a particle monitor. FIG. 27 illustrates an example witheight illumination sources or channels 2771, 2772, 2773, 2774, 2775,2776, 2777, and 2778. The illumination channels have been drawn in FIG.27 with varying shapes to represent different azimuthal angles. Eachillumination channel may include a light emitting element and an opticalshaft. For example, illumination channel 2777 includes a light emittingelement 2785 connected to an optical shaft 2786. Illumination channel2778 includes a light emitting element 2787 connected to an opticalshaft 2788. An illumination source may or may not be associated with aset of quantum dots. An illumination source may emit visible light(e.g., wavelengths ranging from about 390 nm to about 700 nm), UV light(e.g., wavelengths ranging from about 10 nm to about 380 nm), orinfrared light (e.g., wavelengths ranging from about 700 nm to about 1mm).

The light emitting elements and optical shafts for the remainingillumination channels have been omitted for clarity. In other words,additional light emitting elements (not shown) may be installed inadditional illumination channels 2771-2776. Each illumination source hasan illumination axis that intersects the particle inspection zone 2740.Illumination axes corresponding to different illumination sources mayvary in azimuthal angle as well as angle with respect to an optical axispassing through a particle inspection zone 2740 having particles 2730,through a lens assembly, and to a camera sensor. Having may differentillumination axes further provides for other dimensions of analysis. Forexample, the lengths of different shadows resulting from shining lightat different angles can indicate the height of a particle.

The light emitting elements may vary in the nature of their emittedlight. For example, illumination hardware 224 (FIG. 2) may provide localprocessor 240 many illumination options such as white-lightillumination, UV illumination, infrared illumination, and visible lightilluminations of various color characteristics. Local processor 240 mayactivate individual light sources one-at-a-time, or activate two or morelight emitting elements simultaneously or concurrently.

FIG. 28 shows a plot combining camera-sensor sub-pixel spectralcharacteristics as shown in FIG. 19 with illumination source spectralcharacteristics. Vertical axis 2807 represents the quantum efficiency(percentage of photons resulting in one electron of current) of a camerasensor sub-pixel. Horizontal axis 2809 represents optical wavelengthswithin the visible spectrum from violet at the left to red at the right.The dot-dot-dashed curve 2830 represents the spectral response of red or“R” sub-pixels of an RGB camera sensor. The dot-dashed curve 2840represents the spectral response of green or “G” sub-pixels of an RGBcamera sensor. The dashed curve 2850 represents the represents thespectral response of blue or “B” sub-pixels of an RGB camera sensor.FIG. 28 shows the quantum efficiency curves for red, green and bluecamera sensor sub-pixels. Relative to FIG. 19, the horizontal wavelengthaxis has been extended in FIG. 28 to include ultraviolet (UV) light atshorter wavelength and near infrared (IR) light at longer wavelengths.

FIG. 28 adds emission spectra of value illumination sources (for whichthe vertical axis has arbitrary units unrelated to quantum efficiency).Heavy solid curve 2810 is representative of the emission spectra ofwhite-light LEDs. White-light LEDs are fundamentally blue LEDS, hencethe emission peak in the blue, to which phosphors have been added toconvert much of the blue light into a broad spectrum of longerwavelength light, hence the broad spectral peak to the right.

In many embodiments, such a white-light LED is the primary illuminationsource used to produce images for particle shape (morphology) analysisas well as a basic, first pass color analysis. This first pass coloranalysis is largely based on color as perceived by the human eye. It isworth keeping in mind, there is much more color information that can beperceived by the human eye.

Curve 2820 represents the emission spectra of a blue LED. While awhite-light LED may be used to excite fluorescence of quantum-dots, itis more efficient to do so with a blue LED.

Curve 2832 represents the emission spectrum of quantum dots tuned duringmanufacture to emit red light at the absorption peak of chlorophyll-awithin grains of grass-pollen. This “chlorophyll-a red” emission may befluorescently exited by, for example, light from a blue LED, or exciteddirectly electronically. Curves 2834 and 2836 illustrate spectra ofquantum-dots tuned to emit light of wavelengths just above and justbelow the chlorophyll-a red wavelength.

A strong signature for the presence of chlorophyll-a is strong opticalabsorption of red light of the spectrum of curve 2832 but not of redlight of the spectrum of curves 2834 and 2836.

An approximation of full spectral analysis of objects viewed with acamera sensor is possible with a sufficient number of quantum-dotillumination sources. Consider, as an example, extending the set ofspectral curves 2834, 2832 and 2836 in both directions of increasing anddecreasing wavelength in order to cover the entire visible spectrum.While not providing the same fine color resolution of a scientific gradespectrometer, a device with between 10 and 100 quantum-dot illuminationsources may still provide an approximation of a full spectral analysisat each camera-sensor pixel location that provides useful information atrelatively low cost.

Even for analysis of shape information (morphological analysis) thatdoes not make use of color, the narrow spectral widths of quantum-dotemission may be helpful. Consider, as an example, a lens system that issubject to chromatic aberration, either as a cost saving measure or dueto the use of an electronically controlled variable lens (in combinationwith a stronger fixed lens). In such a scenario, illumination with thegreen quantum-dot spectrum of curve 2845 will largely eliminatechromatic aberration effects and produce sharper images formorphological analysis.

Useful spectral information is not limited to the visible spectrum. Forexample, it may be of interest to illuminate particles of interest witha near infrared LED, for example, at a wavelength of 850 nm. Asillustrated by curve 2855, sufficiently “near” infrared light, that iswith sufficiently short wavelengths, may still be transmitted by commonlens materials and be detectable by a conventional camera-sensors. Insome applications, the near infrared properties of particles may be ofvalue.

Typically, common lens materials block ultraviolet light. This may beused to advantage when particles of interest are illuminated by UVlight, resulting in fluorescent light of longer wavelengths that aredetected by the camera-sensor while the illuminating UV is not. Thisisolates the interesting fluorescence signal from simply scattered UVlight. UV fluorescence is of particular value in distinguishing betweeninorganic particles and particles of biological origin.

Curve 2860 is representative of common 365 nm UV LEDs. This UVwavelength is sufficiently short to fluorescently excite nicotinamideadenine dinucleotide (NADH) molecules, but too long to excite otherbio-molecules, hence a 365 nm UV LED can be used to probe NADH contentof biological particles of interest.

Curve 2862 represents the emission spectra of a shorter wavelength UVLED, with the ability to fluorescently exits trytophan and otheraromatic amino acids within proteins.

By probing both NADH and protein content, a pair of UV LEDs provides atwo-dimensional probe of particle biochemistry. In a like manner and forsimilar purposes, additional UV LEDs may be included where each UV LED(or cluster of UV LEDs) emits UV light of differing energies. While muchless powerful then a wet-laboratory bio-assay, such optical probing ofparticle biochemistry has the advantage of providing immediate, ifcrude, biochemical information, with which to aid in real-time particletype discrimination.

In a specific embodiment, a feature of the system enables the use oflow-cost lens systems within particle imaging systems by relaxing therequirements for achromatic optics. An achromatic lens is a lens that isdesigned to limit the effects of chromatic aberration. Quantum dots canhelp with chromatic aberration. Generally, however, not all colors willbe in complete focus and the performance of an achromatic lens can varyin proportion to its cost.

FIG. 29 shows an example of an achromatic lens and its operation. Asshown in the example of FIG. 29, there is an achromatic lens 2910 withan aperture 2915 of diameter D, objects in an object plane 2920, and anRGB sensor plane 2925. The achromatic lens imperfectly brings objects inthe object plane to a focus at the RGB sensor plane. In this example,green light 2930 indicated by dashed lines is brought to a sharp focusat RGB sensor plane 2925. Red light 2935 indicated by dotted lines isnot. Ray traces common to both colors are indicated by solid lines.

For example, both green and red light follow the path of a central ray2940. For example, if achromatic lens 2910 is made of a single materialwith an index of refraction that decreases with increasing wavelengths(as is typical of most transparent materials), and if distances u and vare adjusted to bring green light 2930 to a focus at RGB sensor plane2925, red light 2935 will not come to a sharp focus and itscorresponding image will be blurred by a spot size of diameter “a” asindicated by arrows 2950.

Defying conventional practice with RGB camera systems, in some cases itis sufficient for particle shape analysis to enable a sharp focus imagefor one color only; useful color analysis may be performed with the aidof other color images, even if they are somewhat blurred.

The requirements for achromatic optics may be further relaxed viaparticle (e.g., pollen or mold spore) sample illumination by theselected color using a light source with a narrow spectral width. Anarrow band of illumination as provided by the quantum dots facilitatesgenerating a very sharp image for a particular color. For example, in alens having achromatic aberrations where all colors do not come intocomplete focus, the camera sensor can be focused for a particular color(e.g., wavelength) in order to generate a very sharp image in thatparticular color. In other words, particles captured within the imagewill be sharply defined which, in turn, facilitates the morphologicalanalysis.

While for many scientific optical spectrometer applications, lightemitted from quantum dots would not be considered as narrow in spectralwidth, for the purpose of enabling low-cost lens systems with relaxedtolerances on chromatic aberrations, and relative to the native spectralwidths of RGB color sensitivities of common digital camera sensors,quantum dots do provide a useful “narrow” spectral width. In anotherspecific embodiment, systems and techniques are provided to enrich thecolor spectral information captured by RGB color camera sensors with theaid of quantum dots.

System and techniques are provided to reliably identify or discriminateparticles based on images of the particles where the images have beencreated using low-cost RGB camera systems. In an embodiment, an airborneparticle monitor includes a low-cost RGB camera system which generatesfirst and second images of particles that have been collected. Theimages are color-images. In the first image, one color at most is infocus. In the second image the particles have been illuminated usinglight emitted from quantum dots. A first analysis is performed on thefirst image to generate a listing of candidate particles. The firstanalysis is based on geometric features that have been captured in thefirst image. The geometric features may include size, shape, surfacetexture, or combinations of these. A second analysis is performed on thesecond image to narrow the listing of candidate particles. The secondanalysis is based on color features that have (or have not) beencaptured in the second image.

In a specific embodiment, a particle or digital optical imaging systemincludes an image sensor, a lens assembly and an illumination source.Particles may be collected on the surface of a slide and illuminated bya set of light sources from above, below, or both. A lens or lensassembly images, through an iris defining the aperture of the lensassembly, the particles on an image sensor.

In a specific embodiment, the image sensors that can be used have beendeveloped and are mass-produced for digital cameras including digitalcameras built into smart phones. These silicon chip devices providemega-pixel RGB images at relatively low cost. A representative pixelpitch for such sensor chips is 1.4 microns. These powerful and low-costimage sensors can be used for the purpose of enabling low-cost automatedparticle (e.g., pollen or mold spore) monitoring systems.

Because particles such as pollen grains are typically only tens ofmicrons in diameter, in a specific embodiment, it is generallypreferable for the imaging system to provide some magnification betweenthe sampled pollen and its image at the imaging sensor. For example, toprovide a factor of four magnification, the distance from the lensassembly to the image sensor for the image sensor may be about fourtimes the distance from the lens assembly to the sampled pollen. Asimage resolution approaching the wavelength of light is desired,diffraction limited optics with relatively large apertures may beneeded. This makes the problem of chromatic aberrations more difficult.

Optics based on low-cost plastic molded parts using only one type ofplastic is desirable from a cost perspective. However, such low-costlens constructions will typically suffer significant chromaticaberration, particularly if large apertures are required. Generally,such low-cost plastic molded lens systems would not be an option forairborne particle (e.g., pollen or mold spore) imaging systems.Applicants have appreciated, however, that in some cases of airborneparticle imaging, it is sufficient if only one of the RGB color imagesis in sharp focus.

In a specific embodiment, the middle color green is desired as being thecolor with the sharp focus. In other specific embodiments, red or bluemay be desired as being the color with the sharp focus. In a specificembodiment, a pollen imaging system includes a molded plastic lenses isoptimized for green light at the expense of allowing considerablechromatic aberration for red and blue light.

As discussed, in conventional color optics systems this would beunacceptable, but for the purpose of distinguishing between types ofpollen and between pollen and other particulates, applicants haveappreciated that in some cases it is sufficient to use a sharp greenimage to provide shape or geometry information, i.e. morphologicalinformation, with which to distinguish between particle types and thenuse somewhat blurred red and blue images as well to determine colorinformation with which to distinguish between particle types. In otherwords, applicants have appreciated that for particle (e.g., pollen ormold spore) imaging it can be acceptable in some cases for the optics toprovide somewhat blurred red and blue images provided that the greenimage is sharp.

In some cases, applicants have found that if the optics are designed forsharpest focus for red light rather than green light, then the blueimage will suffer further blurring. Similarly optimizing optics for bluerather than green will increase blurring of the red image. Theseconsiderations favor the choice of green light for the sharp focusimage. Nevertheless, in some circumstances it may be appropriate todesign optics to provide a sharp focus for red light or blue light.

For example, if near-infrared as well as visible pollen colorinformation is desired, it may be desirable to minimize or reducechromatic aberration for red so that the near-infrared images are nottoo blurred. On the other hand, seeking a sharp focus for blue may beappropriate if quantum dots are not used and a white LED is used with anarrow blue spectral peak. Thus, it should be appreciated that whilesome embodiments are shown and described in conjunction with providing asharply focused green image, other embodiments provide for a sharplyfocused red image or a sharply focused blue image, or other wavelength.

The relatively broad spectral width of light received by green RGBcamera sensor pixels may well lead to serious chromatic aberrationproblems even for the green image.

In a specific embodiment, the sampled pollen is sequentially illuminatedby a laser light source and a white light source such as a conventionalwhite LED. The lens assembly is optimized or designed to minimize orreduce aberration for light at the laser's wavelength. A sharp-focusedimage is captured during sample illumination by the laser. If, forexample, the laser is red then red camera sensor pixels are used tocapture the sharp image and if the laser is green then green camerasensor pixels are used. Particle (e.g., pollen or mold spore) colorinformation with which to distinguish between particulate types is thencollected during sample illumination by a white LED. However, in someapplications it is desirable to avoid the expense of a laser lightsource.

In a specific embodiment, quantum dots are used to provide a low-costalternative for providing narrow spectral width light sources. Forexample, quantum dots may be used to provide a narrow spectral widthgreen light source. The combination of allowing blurred red and blueimages plus the use of quantum dots to provide a narrow-spectral-widthgreen-light illumination source enable the use of low-costsingle-plastic lenses in a particle (e.g., pollen or mold spore) imagingsystem.

Table D below shows an illumination sequence for sharp image and colormeasurement. Table D below considers a specific scenario in which aparticle imaging system collects a sharply focused image at one color aswell as capturing particle color information at other colors. In thisscenario there are two light sources that are alternately illuminatingthe sampled particle. A first light source in an illumination sequenceincludes quantum dots and produces green light with a narrow spectrum.While this quantum-dot green light source is activated the green pixelsof the RGB camera sensor captures a sharply focused image of the pollengrains for shape analysis. Green can be desirable because it'swavelengths are between blue and red. After this quantum-dot green lightsource is turned off, a white light source is activated enablingbroad-spectrum red, green and blue images to be simultaneously capturedby the RGB camera sensor for pollen color analysis.

It should be appreciated that the sequence of illumination may beswapped. For example, the illumination sequence may include activing thewhite light, capturing a first image of the particles under the whitelight, de-activating the white light, activating the green light, andcapturing a second image of the particles under the green light.

TABLE D Illumination Illumination RGB sequence source pixels used Colorimaged 1 Quantum-dot GREEN Narrow-spectrum green green 2 White RED red 2White GREEN green 2 White BLUE blue

An alternate to the scenario of table D is to have only one light sourceincluding green quantum dots resulting in generation of a strong narrowspectral peak of green light superposed on broad spectrum of whitelight. In this case, the RGB camera sensor green image will capture asuperposition of a sharp quantum-dot-green image and a less stronglyfocused green image; in some cases this will be acceptable if not idealfor particle (e.g., pollen or mold spore) shape recognition.

In a further refinement of this alternate scenario, the white lightsource also contains red and blue quantum dots as well as green quantumdots so that the light output of the light source is concentrated inthree narrow spectral peaks; this will reduce the contamination of thegreen RGB camera sensor image from light that is not from the greenquantum dots.

In a specific embodiment, a particle imaging system incorporates quantumdots into the light sources. In one approach, a film containing quantumdots is placed between the particle (e.g., pollen or mold spore) sampleand a light source such as an LED, thus sharpening the spectral peaksrelative to the original light source. In another approach, the quantumdots are electrically excited to directly create light with desiredspectral properties; for example, quantum dots may be the light emittingelements within an LED.

In some cases, it may be desirable to include an auto-focus mechanism,or more generally an adjustable focus mechanism under software control,within particle monitoring system 105. A suitable auto-focus mechanismis a “liquid lens” as available from Varioptics of Lyon, France. FIG. 30shows a sealed cell in an off-state. FIG. 31 shows the sealed cell in anon-state. Referring now to FIG. 30, the sealed cell includes oil 3010,water 3020, an upper transparent window 3030, a lower transparent window3040, and electrodes 3060.

The oil is of a high refractive index and is trapped, along with thewater, between the upper and lower transparent windows. There is a thinwater repellent surface 3050 between the oil and water and the effectsof surface tension, result in the oil/water boundary taking a shape suchthat the oil is shaped into a diverging lens when electrode 3060 isuncharged.

The result is that if a parallel one axis light ray 3070 and off-axislight rays 3080 enter the device, the off axis light rays 3080 willdiverge from the on-axis ray 3070 upon exiting the device.

Referring now to FIG. 31, if electrode 3060 is charged, it will attractthe water 3020 due to water's high dielectric constant reshaping the oil3010 into a converging lens as illustrated by the on-axis ray 3070 andoff-axis rays 3080. The device is cylindrically symmetric about theon-axis ray 3070. As one of skill in the art would recognize, thediagrams shown in FIGS. 30 and 31 are schematic for conceptual clarityand the geometry of the electrodes can be more complex.

Addition of an auto-focusing mechanism adds to the complexity ofproviding achromatic optics, hence the methods presented above forrelaxing the tolerances for chromatic aberrations become more beneficialif the system includes an auto-focus or adjustable focus mechanism suchas a liquid lens.

Having addressed the issue of providing at least one sharp color imagefor measuring shape features of pollen and other particulates, let usnow turn our attention to techniques or means to enhance the colorinformation available to distinguish between types of pollen and otherparticles.

With particle samples illuminated with a white light source, an RGBcamera sensor provides three images. In principle, one could redesignthe camera sensor with additional types of color pixels to become, forexample, an RYGBV (red, yellow, green, blue, violet) camera sensor, butwithout the mass market of color digital cameras behind it, this wouldbe a very expensive solution for particle imaging systems.

Consider, as an example, examining the yellow component of a pollenimage with an RGB camera sensor. If a pollen sample is illuminated witha pure yellow light source, an image of the yellow color component of apollen grain will be captured by both the green and red pixels of theRGB camera sensor. Quantum dots can provide at low cost such a source ofpure yellow, and other pure colors. With a set of N sequentiallyactivated quantum-dot enhanced light sources, pollen grains may beimaged at N different colors. Note that N may be larger the 3 (thenumber of colors nominally supported by an RGB camera sensor). Forexample, Table E below shows an illumination sequence for N=9 colors toprovide an example with 9 colors.

TABLE E Illumination sequence Illumination source RGB pixels used Colorimaged 1 Red RED Red 2 Red-orange RED Red-orange 3 Orange RED Orange 4Yellow-green GREEN Yellow-green 5 Green GREEN Green 6 Blue-green GREENBlue-green 7 Blue BLUE Blue 8 Blue-violet BLUE Blue-violet 9 Violet BLUEViolet

In a specific embodiment, the quantum dots are spherical in shape. Inanother specific embodiment, the quantum dots are non-spherical inshape. In particular, quantum dots may have an elongated shape. Quantumdots of an elongated shape are often referred to as “quantum rods.”Elongated quantum dot shapes may be used to improve quantum dot lightgenerating efficiency. Furthermore, while spherical quantum dots emitunpolarized light, elongated quantum dots may be used to emit linearlypolarized light.

As an example, the nine step illumination sequence of table E may beexpanded to an eighteen step illumination sequence corresponding toeighteen quantum dot illumination sources where each illumination colorof table E corresponds to two illumination sources of differing linearpolarization orientations. Optionally, polarizers may be placed in theoptical paths to a camera sensor or other type of optical sensor. Apollen monitor with polarized quantum dot (quantum rod) illuminationsources may provide enhanced allergenic particle detection anddiscrimination via measurements of the interaction of detectedparticulates with polarized light. A pollen monitor may include acombination of quantum dots having a spherical shape and quantum dotshaving an elongated shape.

While the cleanest separation of pollen image color components isprovided when each quantum-dot color source is activated one at a time,in some cases it may be advantageous to more rapidly scan the set of Nillumination colors. This is possible by taking advantage of the factorthat RGB cameras sensors are designed to capture three colorssimultaneously.

For example, consider the scenario given in table F below. A first LEDlight source contains three sets of quantum dots, one set emitting at ared wavelength, another set emitting at a yellow-green wavelength and athird set emitting at a blue wavelength. When this first LED lightsource is activated the red pixels of the RGB camera sensor will respondmost strongly to the red wavelength, the green pixels to theyellow-green wavelength and the blue pixels to the blue wavelength.

Hence images may be simultaneously captured for the threecolor-components of this first LED as indicated by a common illuminationsequence number “1” for red, yellow-green and blue in table F. A secondLED light source contains another three sets of quantum dots that emitwavelengths corresponding to the colors of red-orange, green andblue-violet. When this second LED is activated, the RGB camera sensorsimultaneous captures images corresponding to the second set of quantumdot colors. Similarly for a third LED contains three sets of quantumdots corresponding the colors orange, blue-green and violet. Hence withonly three LEDs that are sequentially activated, images for ninedifferent spectral components of pollen color may be captured. Manyother options exist for combining more than one quantum-dot color in oneillumination step.

TABLE F Illumination RGB pixels sequence Illumination source used Colorimaged 1 LED #1 (red/yellow-green/blue) RED Red 1 LED #1(red/yellow-green/blue) GREEN Yellow-green 1 LED #1(red/yellow-green/blue) BLUE Blue 2 LED #2(red-orange/green/blue-violet) RED Red-orange 2 LED #2(red-orange/green/blue-violet GREEN Green 2 LED #2(red-orange/green/blue-violet) BLUE Blue-violet 3 LED #3(orange/blue-green/violet) RED Orange 3 LED #3(orange/blue-green/violet) GREEN Blue-green 3 LED #3(orange/blue-green/violet) BLUE Violet

Let us consider in more detail the effects of color crosstalk for theillumination sequence given in table F. Color crosstalk may bemathematically expressed with the following matrix equations. The columnvectors to the left represent the RBG camera sensor response for thethree types of pixels. For example GREEN₂ represents the signalamplitude response of green pixels when the pollen sample is illuminatedwith LED #2 of table F. To the far right are column vectors representingthe strengths of the quantum-dot illumination sources within an LED oftable F. To the immediate right of the equal signs are weightingmatrices corresponding to each of the three LEDs. For example, W₂(BLUE,red orange) gives the strength of response of blue camera pixels to thecolor of light from the red-orange quantum dots. These equations expressthat fact that due to color crosstalk, red, green and blue camera imagescorrespond to weighted mixtures of the quantum-dot colors.

$\begin{bmatrix}{RED}_{1} \\{GREEN}_{1} \\{BLUE}_{1}\end{bmatrix} = {\quad{\begin{bmatrix}{W_{1}( {{RED},{red}} )} & {W_{1}( {{RED},{{yellow}\mspace{14mu}{green}}} )} & {W_{1}( {{RED},{blue}} )} \\{W_{1}( {{GREEN},{red}} )} & {W_{1}( {{GREEN},{{yellow}\mspace{14mu}{green}}} )} & {W_{1}( {{GREEN},{blue}} )} \\{W_{1}( {{BLUE},{red}} )} & {W_{1}( {{BLUE},{{yellow}\mspace{14mu}{green}}} )} & {W_{1}( {{BLUE},{blue}} )}\end{bmatrix} \times {\quad{{\begin{bmatrix}{red} \\{{yellow}\mspace{14mu}{green}} \\{blue}\end{bmatrix}\lbrack \begin{matrix}{RED}_{2} \\{GREEN}_{2} \\{BLUE}_{2}\end{matrix} \rbrack} = {\quad{\quad{\quad{\begin{bmatrix}\begin{matrix}{W_{2}( {{RED},} } \\ {{red}\mspace{14mu}{orange}} )\end{matrix} & {W_{2}( {{RED},{green}} )} & \begin{matrix}{W_{2}( {{RED},} } \\ {{blue}\mspace{14mu}{violet}} )\end{matrix} \\\begin{matrix}{W_{2}( {{GREEN},} } \\ {{red}\mspace{11mu}{orange}} )\end{matrix} & {W_{2}( {{GREEN},{green}} )} & \begin{matrix}{W_{2}( {{GREEN},} } \\ {{blue}\mspace{14mu}{violet}} )\end{matrix} \\\begin{matrix}{W_{2}( {{BLUE},} } \\ {{red}\mspace{11mu}{orange}} )\end{matrix} & {W_{2}( {{BLUE},{green}} )} & \begin{matrix}{W_{2}( {{BLUE},} } \\ {{blue}\mspace{14mu}{violet}} )\end{matrix}\end{bmatrix}{\quad{\times {\quad{\quad{{\begin{bmatrix}{{red}\mspace{14mu}{orange}} \\{\mspace{14mu}{green}} \\{{blue}\mspace{14mu}{violet}}\end{bmatrix}\lbrack \begin{matrix}{RED}_{3} \\{GREEN}_{3} \\{BLUE}_{3}\end{matrix} \rbrack} = {\quad{\quad{\quad{\begin{bmatrix}\begin{matrix}{W_{3}( {{RED},} } \\ {orange} )\end{matrix} & \begin{matrix}{W_{3}( {{RED},} } \\ {{blue}\mspace{14mu}{green}} )\end{matrix} & \begin{matrix}{W_{3}( {{RED},} } \\ {violet} )\end{matrix} \\\begin{matrix}{W_{3}( {{GREEN},} } \\ {orange} )\end{matrix} & \begin{matrix}{W_{3}( {{GREEN},} } \\{ {{blue}\mspace{20mu}{green}} )\mspace{11mu}}\end{matrix} & \begin{matrix}{W_{3}( {{GREEN},} } \\ {violet} )\end{matrix} \\\begin{matrix}{W_{3}( {{BLUE},} } \\ {orange} )\end{matrix} & \begin{matrix}{W_{3}( {{BLUE},} } \\ {{blue}\mspace{14mu}{green}} )\end{matrix} & \begin{matrix}{W_{3}( {{BLUE},} } \\ {violet} )\end{matrix}\end{bmatrix}{\quad{\times {\quad{\quad\begin{bmatrix}{orange} \\{{blue}\mspace{14mu}{green}} \\{violet}\end{bmatrix}}}}}}}}}}}}}}}}}}}}}}$

The quantum-dot color components of the RGB camera images may becomputed by solving the above equations. This is can be done by firstmultiplying the above questions by the inverses of the weightingmatrices, and then applying the resulting matrix equations below. If anillumination source contains less than three color sources, the threeRGB camera images will provide redundant information with which toseparate the image contributions from each color source. If anillumination source contains more than three quantum-dot colors, wemathematically have only three questions to determine more than threeunknowns and hence the three RGB camera color images are insufficient tofully separate out the contributions of the more than three quantum-dotcolors; nevertheless there may be cases in which the use of more thanthree quantum-dot colors within a single LED may contribute to usefulenrichment of pollen color for the purpose of distinguishing betweentypes of pollen (or other particles).

$\quad{\begin{bmatrix}{red} \\{{yellow}\mspace{14mu}{green}} \\{blue}\end{bmatrix} = {( W_{1} )^{- 1} \times \begin{bmatrix}{RED}_{1} \\{GREEN}_{1} \\{BLUE}_{1}\end{bmatrix}{\quad{\begin{bmatrix}{{orange}\mspace{14mu}{red}} \\{\mspace{14mu}{green}} \\{{blue}\mspace{14mu}{violet}}\end{bmatrix} = {( W_{2} )^{- 1} \times \begin{bmatrix}{RED}_{2} \\{GREEN}_{2} \\{BLUE}_{2}\end{bmatrix}{\quad{\begin{bmatrix}{orange} \\{{blue}\mspace{14mu}{green}} \\{violet}\end{bmatrix} = {( W_{3} )^{- 1} \times \begin{bmatrix}{RED}_{3} \\{GREEN}_{3} \\{BLUE}_{3}\end{bmatrix}}}}}}}}}$

LED #1 of table F, for example, may contain three types of quantum dotsas locations for electron-hole recombination resulting in emission ofred, yellow-green and blue photons. Alternatively the LED might be aconventional white, blue or ultraviolet LED whose light passes through afilm containing red, yellow-green and blue quantum dots before reachingthe sampled pollen.

As yet another alternative for generating the nine color images of tableF, light from one and only one conventional white, blue or ultravioletLED may be intercepted by a disk that may be rotated so as tosequentially place a red/yellow-green/blue quantum-dot film, ared-orange/green/blue-violet quantum-dot film and anorange/blue-green/violet quantum-dot film in the light path from the LEDto the sampled particles (e.g., pollen or mold spores).

FIG. 32A shows an example of a disk having regions of differently sizedquantum dots that may be included in one embodiment of particle monitor105. FIG. 32A shows a plan view of a disk 3205 having a set of regionsor sections 3215A-C. A first region 3215A includes a first set ofquantum dots 3220A of a first size (e.g., diameter) dispersed within. Asecond region 3215B includes a second set of quantum dots 3220B of asecond size dispersed within. A third region 3215C includes a third setof quantum dots 3220C of a third size dispersed within. There can be aspindle connected to a center 3225 of the disk. The spindle rotates orturns the disk so that a particular region can face the light emittingelement in order to convert the light emitted from the light emittingelement into the particular colored light desired for illuminating thecollected particles.

The first size is different from the second, and third size. The secondsize is different from the third size. In the example shown in FIG. 32A,the size of the first set of quantum dots is greater than the size ofthe second and third sets of quantum dots. The size of the second set ofquantum dots is less than the size of the first and third sets ofquantum dots. The size of the third set of quantum dots is less than asize of the first set of quantum dots and greater than the size of thesecond set of quantum dots.

To make or manufacture the disk, the different regions may be producedas separate individual sub-units and then joined together as a singleunit. The joining may include, for example, gluing each of the first,second, and third individual regions together.

The disk shown in the example of FIG. 32A has been partitioned intothree regions of differently sized quantum dots. It should beappreciated, however, that the disk may be partitioned into any numberof regions of differently sized quantum dots (e.g., two, three, four,five, six, seven, or more than seven regions) Increasing the number ofregions of differently sized quantum dots helps to increase the accuracyof particle identifications, but can also increase the overall size ofthe disk and, in turn, the overall form factor of the particle monitor.Factors to consider in determining the number of regions of differentlysized quantum dots for a disk include the desired form factor of theparticle monitor, the desired accuracy or sensitivity of the particlemonitor in identifying or discriminating particles, the variety ofparticle types desired to be identified, and other factors.

In an embodiment, particle monitor 105 includes a motor, disk, and lightemitting element. The disk is divided into a set of regions. A regioncan include a set of quantum dots where a size (e.g., diameter) of thequantum dots dispersed one region is different from a size of quantumdots dispersed in another region. The disk is connected to the motor andis positioned to receive light from the light emitting element. Themotor rotates (or moves) the disk while the light emitting elementremains stationary or fixed. The disk may be rotated by the motor into afirst position such that a first region of the disk having a first setof quantum dots of a first size faces the light emitting element. Whenlight from the light emitting element hits or is received by a firstside of the disk facing the light emitting element, the light isconverted by the first set of quantum dots and emitted out a second sideof the disk, opposite the first side of the disk, as first convertedlight.

The disk may be rotated by the motor into a second position such that asecond region of the disk having a second set of quantum does of asecond size, different from the first size, faces the light emittingelement. When the light from the light emitting element is received bythe first side of the disk facing the light emitting element, the lightis converted by the second set of quantum dots and emitted out thesecond side of the disk as second converted light, different from thefirst converted light. For example, a wavelength of the first convertedlight may be different from a wavelength of the second converted light.A wavelength of the first converted light may be greater than awavelength of the second converted light. A wavelength of the firstconverted light may be less than a wavelength of the second convertedlight.

A method for particle identification may include rotating the disk tothe first position, capturing a first image of collected particles whenthe collected particles are illuminated by the first converted light,analyzing the first image to identify one or more particles, determiningthat features captured in the first image are insufficient to identifythe particles, in response to the determination, rotating the disk tothe second position, capturing a second image of the collected particleswhen the collected particles are illuminated by the second convertedlight, and analyzing the second image to identify the one or moreparticles. The features may include colors or color information that hasbeen captured (or not captured) by the images.

In another specific embodiment, a light emitting element rotates (ormoves) and a disk having regions of quantum dots of different sizesremains stationary. In this specific embodiment, particle monitor 105includes a motor, disk, and light emitting element. The disk is dividedinto a set of regions, each region having a set of quantum dots of asize different from quantum dots of another region. The light emittingelement is connected to the motor and is positioned to shine lighttowards the disk. The light emitting element may be rotated by the motorinto a first position. In the first position, light from the lightemitting element is received by a first region having a first set ofquantum dots of a first size dispersed within. The first set of quantumdots convert the light and emit first converted light. The lightemitting element may be rotated into a second position, different fromthe first position. In the second position, light from the lightemitting element is received by a second region having a second set ofquantum dots of a second size, different from the first size, dispersedwithin. The second set of quantum dots convert the light and emit secondconverted light, different from the first converted light. In anotherspecific embodiment, the motor may be omitted and the disk, lightemitting element, or both may be rotated or moved manually such as by auser.

It should be appreciated that the disk having regions of differentquantum dot sizes may instead be replaced by a film having regions ofdifferent quantum dot sizes. The film can be of any shape and notnecessarily disk- or circular-shaped. For example, the film can beshaped as a rectangle, square, triangle, or any other shape asappropriate. In an embodiment, both the disk (or film) having regions ofdifferent quantum dot sizes and the light emitting element may move. Themovement may be a rotation, translation, or both.

In another specific embodiment, particle monitor 105 includes removablequantum dot containing films. For example, there can be first and secondfilms. The first film includes a first set of quantum dots having afirst size. The second film includes a second set of quantum dots havinga second size, different from the first size. The user can swap betweenthe first and second films in order to illuminate the particles underdifferent lighting using the same light emitting element. That is, theuser can remove the first film from the particle monitor and insert thesecond film into the particle monitor (and vice-versa).

For example, the particle monitor may capture a first image of thecollected particles when the particles are illuminated by light emittedfrom the first film. If the particle monitor determines that theparticles cannot be identified based on features captured in the firstimage, the particle monitor may prompt the user to remove the first filmand insert the second film. For example, the particle monitor maydisplay the message, “Particle identification not successful. Pleasereplace quantum-dot containing film A with quantum-dot containing filmB.” Once the user has replaced the first film with the second film, theparticle monitor may capture a second image of the collected particleswhen the particles are illuminated by light emitted from the secondfilm.

In an embodiment, removable films containing quantum dots may be removedand replaced by the user without use of tools. For example, a removablefilm containing quantum dots may be snap-fitted into place within theparticle monitor, or may slide along a track within the particlemonitor. In another embodiment, a removable film containing quantum dotsmay be attached within the particle monitor using fasteners such asscrews, bolts, and nuts. In this embodiment, tools (e.g., screw driver)may be used by the user to swap-in different films. For example, theparticle monitor housing may be designed to be removable so that theuser can access internal components of the monitor (e.g., access aremovable film having quantum dots).

FIG. 32B shows a cross section of a film 3240 having two sets of quantumdots of different sizes. In the example shown in FIG. 32B, there is amatrix material (e.g., a clear polymer) 3245 in which first and secondsets of quantum dots 3250A-B have been dispersed or mixed in. The firstset includes quantum dots having a first size (e.g., first diameter).The second set includes quantum dots having a second size (e.g., seconddiameter), different from the first diameter. For example, the firstsize may be greater or less than the second size. A quantum dot filmsuch as shown in FIG. 32B can be used to emit two different colors(e.g., green and red) simultaneously. In other words, there can be asingle film having both large and small quantum dots. A single film maycontain any number of sets of quantum dots where quantum dots in one setare of a different size (e.g., diameter) than quantum dots in anotherset.

FIG. 32C shows a cross section of two films 3260A-B that have beenstacked together to form a stack 3262. The quantum dots shown in FIG.32C are similar to the quantum dots shown in FIG. 32B. In the exampleshown in FIG. 32C, however, the different sets of quantum dots have beenplaced in separate films. In particular, first film 3260A includesquantum dots 3265A having a first size (e.g., first diameter). Secondfilm 3260B includes quantum dots 3265B having a second size (e.g.,second diameter), different from the first size. A stack of quantum dotfilms as shown in the example of FIG. 32C may likewise be used to emittwo different colors simultaneously. A stack may include any number ofquantum dot films. A stack may include two or more films. A film in thestack may include at most one set of quantum dots of a particular size.A film in the stack may include two or more sets of quantum dots, eachset having a quantum dot size that is different from a quantum dot sizein another set.

Since, for example, the green subpixels in the camera sensor are theones that respond most strongly to green light, and the red subpixels inthe camera sensor are the ones that respond most strongly to red light,the green and red lights may be illuminated sequentially (e.g., one at atime) or simultaneously. Cross-talk may be compensated throughmathematical equations.

Auto-focus mechanisms (such as shown in FIGS. 30-31) may be used notonly to assure the best focus possible for the color selected for themost sharply focused image, but also to improve the focus for othercolor images. The out-of-focus problem for the non-optimized colors canbe addressed by applying the auto-focus function at these non-optimizedcolors.

For example, for the illumination sequence given in tables E and F, anauto-focusing mechanism may be used to improve the resolution of each ofthe nine color images captured; in this case the narrow spectral widthof each of the quantum dot light sources enhance the sharpness of eachauto-focused color image.

For the illumination sequence given in table F, where each illuminationsource contains multiple quantum-dot colors, auto-focusing may be used,for example, to optimize the sharpness of the green RGB sensor pixelimages individually for each of the yellow-green, green and blue-greenillumination source components. Again referring to the illuminationsequence given in table F, during illumination by LED #1, the red RGBsensor pixel image may be captured after auto-focusing the red pixelimage and similarly for the green and blue RGB pixel images, and thenauto-focusing three times again during the illumination by LED #2 andthree more time for LED #3. The narrow spectral width of quantum-dotlight sources enhances the benefits of scenarios in which auto-focusingmechanism is used for more than one color image.

In some cases of pollen imaging system design, it is desirable tocollect enriched pollen color information for use in distinguishingbetween types of pollen and of secondary importance to minimize orreduce the cost of the lenses. In such cases it may be appropriate toaccept the expense of achromatic lens systems in order to obtain thebenefit of sharp pollen images at all wavelengths of light.

A discussion of chromatic aberration from a more quantitativeperspective is provided below. Referring back to FIG. 29 a schematic ofan optical system is shown. As discussed, there is a “pollen” objectplane 2920 and an “RGB sensor” image plane 2925 with a thin lens 2910with an aperture 2915 of diameter D in between. Furthermore, let thethin lens have one flat surface and one surface with a radius ofcurvature R. Let u be the distance from the pollen object plane to thelens and v be the distance from the lens to the RGB sensor image plane.

If the thin lens has a focal length f, then the following focal lengthequation applies.

$\frac{1}{f} = {\frac{1}{u} + \frac{1}{v}}$

If we let M be the magnification, e.g., the ratio of the size of apollen image at the RGB sensor to the actual size of the pollen grain atthe object plane, then M is related to u and v as follows.

$M = \frac{v}{u}$

Eliminating u in the above two equations gives us the followingequation.

$\frac{v}{f} = ( {1 + M} )$

The Lens Maker's Equation for focal length of a lens as a function ofits shape and index of refraction is as follows where d is the thicknessof the lens and R₁ and R₂ are the radii of curvature of the lenssurfaces.

$\frac{1}{f} = {( {n - 1} )\lbrack {\frac{1}{R_{1}} - \frac{1}{R_{2}} + \frac{( {n - 1} )d}{{nR}_{1}R_{2}}} \rbrack}$

In the thin lens approximation where d<<R₁ and d<<R₂, the last term inthe square brackets can be neglected so that we have the followingequation. Note that the focal length is inversely proportional to (n−1).

$\frac{1}{f} = {( {n - 1} )\lbrack {\frac{1}{R_{1}} - \frac{1}{R_{2}}} \rbrack}$

For the above sketch where one radius of curvature is infinite and theother radius of curvature is R, this reduces to the following.

$\frac{1}{f} = \frac{( {n - 1} )}{R}$

Combined with the first equation above, we have the following.

$\frac{( {n - 1} )}{R} = {\frac{1}{u} + \frac{1}{v}}$

As suggested in the above sketch, let us assume that things have beenarranged so that a green wavelength of light from the pollen objectplane is sharply focused on the RGB sensor image plane. The index ofrefraction n in the above equations corresponds to this selected greenwavelength. Now also consider a red wavelength with a different index ofrefraction n′=n+Δn which would come to a focus at a distance v′=v+Δvfrom the lens (if the RGB sensor was not in the way). Assuming thepollen object plane to lens distance u to be fixed, differentiating theabove equation gives the following.

$\frac{\Delta\; n}{R} = {- \frac{\Delta\; v}{v^{2}}}$

This in turn implies the following.

${- \frac{\Delta\; v}{v}} = {{v\frac{\Delta\; n}{R}} = {{\frac{v}{f}\frac{\Delta\; n}{( {n - 1} )}} = {( {1 + M} )\frac{\Delta\; n}{( {n - 1} )}}}}$

At the RGB sensor image plane, the red light forms a spot of diameter“a” which by similar triangles is related to the aperture D by the ratioof Δv to v′. Approximating v′ by v, we have the following relation.

$\frac{a}{D} = {\frac{\Delta\; v}{v^{\prime}} \approx \frac{\Delta\; v}{v}}$

This red spot diameter “a” at the image plane is a measure of chromaticaberration. Demagnifying by a factor 1/M so as to refer to more usefullyto dimensions in the pollen object plane, it corresponds to a blurringdiameter of a/M.

The blurring diameter a/M represents the extreme disagreement possiblebetween to rays contributing to the red spot. On average the effects ofchromatic aberration will be less. A more appropriate measure ofblurriness due to chromatic aberration may be obtained by including anappropriate constant factor less than one. Estimating the blurringeffect of chromatic aberration may be as follows.

${{Chromatic}\mspace{14mu}{aberration}} = {{({constant})\frac{a}{M}} \approx {({constant})\frac{D}{M}\frac{\Delta\; v}{v}}}$${{Chromatic}\mspace{14mu}{aberration}} \approx {{({constant}){\;\;}D} + {\frac{( {1 + M} )}{M}\frac{\Delta\; n}{( {n - 1} )}}}$

This blurring of particle (e.g., pollen grain) images due to chromaticaberration in the lens may be one of several factors that blur theimage. Depending on whether the above chromatic aberration is large orsmall compared to other sources of image blurring determines whetherchromatic aberration may be considered significant or negligible.

For example, if the optics in FIG. 29 is designed to produce a sharpimage for a selected green wavelength, then the corresponding image foran alternative wavelength, such as red in the above sketch, may beconsidered to suffer from significant chromatic aberration if thealternative wavelength image is blurred by a factor of two or morecompared to the wavelength selected for the sharpest image. It should beappreciated that such a definition of significant chromatic aberrationis not limited to the thin lens optics shown in FIG. 29.

Another approach to defining significant chromatic aberration mayinclude the aid of the diffraction limit to optical system resolution.Even in the absence of chromatic aberration, basic principles of wavemechanics limit resolution of microscope systems as follows where λ isthe wavelength of the light.

$( {{diffraction}\mspace{14mu}{limit}} ) = {{( {constant}^{\prime} )\frac{\lambda\; u}{D}} = {( {constant}^{\prime} )\frac{( {1 + M} )}{M}f\frac{\lambda}{D}}}$

If the constant is set to a value of one-half, then the above expressionapproximates the Abbe diffraction limit.

The ratio of the above expressions for chromatic aberration anddiffraction limit is as follows.

${Ratio} = {\frac{({constant})}{( {constant}^{\prime} )}\frac{D^{2}}{f\;\lambda}\frac{\Delta\; n}{( {n - 1} )}}$

If this ratio is much less than one, it may be said that chromaticaberration is negligible. On the other hand, if this ratio is two orlarger, then chromatic aberration would significantly interfere with anyattempt to optimize optics so as to reach the diffraction limit. Whilethe above ratio was derived from a simple thin lens system, modernoptics simulation tools would allow one skilled in the art to estimatethe above ratio in more complex systems.

Below let us assume that ratio of the constants above is one-half.Straight-forward simulations with a simulation tool such as Zemax maylead to a more precise value.

For a focal length of 20 mm, and aperture diameter of 5 mm and awavelength of ˜500 nm, the above ratio becomes the following.

${Ratio} \approx {1250\frac{\Delta\; n}{( {n - 1} )}}$

Table G below snows data for an 480R lens as provided by ZeonCorporation of Tokyo, Japan. Such a lens may be used in some embodimentsof particle monitor 105.

TABLE G Wavelength (nm) Abbe Temp 435.835 486.133 546.075 587.562656.273 785.1 number (deg C.) (g) (F) (e) (d) (C) (L.D780) Vd 0 1.53961.5343 1.5300 1.5277 1.5250 56 25 1.5369 1.5317 1.5273 1.5251 1.5224 5640 1.5352 1.5299 1.5257 1.5234 1.5207 1.5174 57 60 1.5329 1.5276 1.52341.5211 1.5184 1.5152 57 80 1.5308 1.5253 1.5214 1.5189 1.5164 1.5132 58

The wavelengths in the columns correspond to the following colors:violet, blue, green, yellow, orange, infrared. If we compare green at546.075 and blue at 486.133 at 25° C., the difference in index ofrefraction is Δn=1.5317−1.5273=0.0044. The index of refraction for greenminus one is 0.5273 so Δn/(n−1)=0.0044/0.5273=0.008344. Multiplying thisby 1,250 gives a ratio of 10, i.e. serious chromatic aberration.

This example is for a difference in wavelength of (546.075−486.133)=60nm. If instead we had a wavelength difference of 15 nm (half of aquantum dot spectral width of 30 nm), the chromatic aberration would bereduced by a factor of 4, for a ratio of 2.5. Still serious chromaticaberration, but significantly improved.

FIG. 33 shows a flow illustrating some basic ingredients of automatedparticle (e.g., pollen) monitoring according to a specific embodiment.This flow chart illustrates a method of pollen detection. In brief, in astep 3310, a pollen monitor samples ambient air such as via a blowerthat sucks in the ambient air. In a step 3320, pollen captured from theambient air is transported to an illumination zone. For example, therecan be a supply reel and a take-up reel to transport a sticky tape withadhesive side up past the air-inlet/blower. Pollen and other particlesthat stick to the adhesive are transported to the illumination zonewhich is provided by one or more illumination sources, some or all ofwhich may incorporate quantum dots.

In a step 3330, one or more illumination colors are selected. In a step3340, the pollen is illuminated. The selection of the illuminationcolors may be based on a pre-determined illumination sequence that isstored by the monitor. The particle (e.g., pollen) monitor access thepre-determined illumination sequence in order to identify the color(e.g., wavelength) of light that should be emitted. The selection can becontrolled by a computer. The computer selects an illumination source(s)with desired spectral properties. This may in effect select a particularset or sets of quantum dots and corresponding wavelengths. The selectedillumination sources are then activated.

In an embodiment, the illumination sequence may be determineddynamically. A method may include illuminating the captured particlesunder white light, while the particles are being illuminated by thewhite light, capturing a first image of the particles, identifying, fromthe first image, colors of the particles, based on the colors of theparticles as revealed by the first image, and selecting another color,different from white, with which to illuminate the particles for asecond image of the particles. For example, RGB images collected underwhite light illumination may contain yellow particles of a shapepossibly indicative of grass pollen grains. As discussed previously, theinterpretation of the imaged pollen grains being grass pollen may thenbe tested by using quantum-dot illumination sources corresponding tospectral curves 2832, 2834 and 2836 of FIG. 28.

In a step 3350, the monitor performs an optical detection. The opticaldetection may include capturing an image of the particles under theillumination. In other words, while the sampled pollen is illuminated, alens array and an RGB camera sensor capture images of the sampledpollen.

Steps 3330-3350 may be repeated 3352 any number of times in order tocapture further color information about the sampled particles (e.g.,pollen) and other detected particulates. In a step 3360, the opticaldata (e.g., images of particles) is analyzed. In a step 3370, theoptical data (e.g., images) may be transmitted to a remote server.

In an embodiment, as discussed above, the particle monitor can beconnected to a network. The connection to a network allows the particlemonitor to receive updates. An update may include, for example, updatesto the illumination sequence, updates to image capture settings, orboth. An illumination sequence stored at the particle monitor mayspecify the order for activing the different illumination sources. Theimage capture settings may specify focal depths or depths of focus. Forexample, three-dimensional morphology information may be obtainedthrough a sequence of depths of focus corresponding to differenthorizontal layers of a translucent particle such as a pollen grain. Theability to update the particle monitor remotely or over a network helpsto ensure use of the latest algorithms for quickly and accuratelyidentifying or discriminating particles.

FIG. 34 shows further detail of a flow for analyzing and identifying ordiscriminating particles that have been collected by the particlemonitor. In a step 3410, the collected particles are illuminated using afirst illumination source. In a step 3415, a camera sensor of amicroscope in the particle monitor captures a first image of theparticles while the particles are being illuminated using the firstillumination source. That is, a processor of the particle monitorrecords on storage image data representative of the particles beingilluminated using the first illumination source. In a step 3420, theparticle monitor analyzes the first image to identify the collectedparticles.

FIG. 35 shows an example of a first image 3505 that may be captured. Thefirst image includes particles 3510A-D that have been captured. Anycompetent image recognition technique may be applied. In a specificembodiment, an analysis includes a morphology analysis in whichgeometric features of the particles are examined. The geometric featuresmay be extracted and compared to a reference library of geometricfeatures of known particle types. Examples of geometric features includesize, shape, surface texture (e.g., smooth surface versus spikeysurface), and so forth.

In a step 3425 (FIG. 34) a determination is made as to whether anidentification of particles from the first image is satisfactory asthere can be many different particles that share the same or similarmorphology. The analysis may include the application statisticalalgorithms to calculate a degree of confidence in the identification ordiscrimination. The calculated degree of confidence may be compared to athreshold confidence level. The degree of confidence can be a percentageor other value. The threshold confidence may be configurable such as bya user or administrator.

If the degree of confidence exceeds the acceptable threshold, anidentification of the particle may be displayed, the results logged, orboth (step 3430).

Alternatively, if the degree of confidence does not exceed or is belowthe threshold, the particle monitor illuminates the collected particlesusing a second illumination source that includes quantum dots (step3435). For example, the first illumination source may be deactivated andthe second illumination source may be activated. The illumination orlighting conditions created by the second illumination source aredifferent than the illumination or lighting conditions created by thefirst illumination source.

In a step 3440, the camera sensor captures a second image of theparticles while the particles are being illuminated using the secondillumination source including quantum dots. In a step 3445, the particlemonitor analyzes the second image to identify the collected particles.In a specific embodiment, the analysis includes analyzing colorinformation recorded in the second image. The analysis may includecomparing the first and second images, comparing the second image to alibrary of reference images, or both.

FIG. 36 shows an example of a second image 3605 that may be captured ofthe particles under illumination provided by the second illuminationsource including quantum dots. In the example shown in FIG. 36,particles 3510A-C remain visible in the second image. Particle 3510D,however, is drawn in broken lines to indicate that its appearance in thesecond image as compared to the first image is faint, missing, or lessperceptible.

Consider, as an example, that the illumination for the second imageincluded red light or, more specifically, that the emitted quantum dotspectrum includes a narrow spectrum centered on a chlorophyll-aabsorption peak such as approximately at 665 nanometers. The spectrummay include a full width half maximum less than 50 nanometers, or lessthan 25 nanometers. In other words, the emitted quantum dot spectrum issubstantially within a chlorophyll-a absorption peak. In the exampleshown in FIG. 36, the appearance of particle 3510D in the second imageas being faint or even missing, absent, less perceptible, or lessvisible is the result of the particle having absorbed the light ratherthan scattering the light. In this example, the analysis of the secondimage can suggest that the particle includes grass pollen because grasspollens typically include chlorophyll-a.

In an embodiment, a method includes identifying an absorption peak of aparticular type of particle, collecting particles floating in anenvironment, illuminating the particles with first light, capturing afirst image of the particles while the particles are illuminated withthe first light, illuminating the particles with second light, differentfrom the first light, the second light being light corresponding to theabsorption peak of the particular type of particle, capturing a secondimage while the particles are illuminated with the second light,comparing the first and second images, based on the comparison,determining that a particle captured in the first image is lessperceptible in the second image than the first image, and identifyingthe particle as being of the particular type of particle.

In a step 3450 (FIG. 34), a determination is made as to whether theidentification is satisfactory. The determination may likewise includecalculating a degree of confidence in the identification, applyingstatistical analyses, comparing the degree of confidence to a thresholdconfidence level, and so forth. The determination may include factoringin or weighing the results from the analysis of the first image. Forexample, if a first result from analyzing the first image stronglyindicates grass pollen, and if a second result from analyzing the secondimage strongly indicates grass pollen, an identification of theparticles as being grass pollen may be satisfactory.

Thus, if the degree of confidence exceeds the acceptable threshold, anidentification of the particle may be displayed, the results logged, orboth (step 3430).

Alternatively, if the degree of confidence does not exceed or is belowthe threshold, the particle monitor obtains and analyzes contextinformation (step 3455). Consider, as another example, that the firstresult from analyzing the first image strongly indicates that theparticles are grass pollen grains but cannot discriminate between twodifferent species of grass. In this case, the particle monitor may issuea request to cloud server 110 for context information such as whichtypes of grass are blooming in the area at the time. Grass types thatare not blooming may be eliminated from consideration. The request mayinclude a geographical location of the particle monitor, a time and dateof particle capture, or both.

The cloud server receives the request and obtains the relevant contextinformation for the requesting particle monitor. The relevant contextinformation may include, for example, weather conditions and windpatterns corresponding to the location and time of particle capture,pollen types known to be presently blooming at the location of therequesting particle monitor, a listing of pollen types identified byother particle monitors that are near the requesting particle monitor,and so forth, or combinations of these.

In a step 3460, a determination is made as to whether the identificationis satisfactory. The determination may likewise include calculating adegree of confidence in the identification, applying statisticalanalyses, comparing the degree of confidence to a threshold confidencelevel, and so forth. The determination may include factoring in orweighing the results from the analysis of the first image, second image,or both.

Consider, as an example, that a first result from analyzing the firstimage indicates grass pollen, a second result from analyzing the secondimage indicates grass pollen, and that the received context informationindicates that grass pollen is currently blooming at the location of theparticle monitor and that grass pollen has recently been detected byother particle monitors near the requesting particle monitor.

In this case, the degree of confidence in the particle as being grasspollen may exceed the acceptable threshold, and an identification of theparticle as being grass pollen may be displayed, the results logged, orboth (step 3430).

Nearby particle monitors may be defined as particle monitors within aspecified radius of the requesting particle monitor. In an embodiment,the cloud server calculates a distance between the requesting particlemonitor and another particle monitor. If the distance is less than thespecified radius, the other particle monitor is considered nearby. Ifthe distance is greater than the specified radius, the other particlemonitor is considered not nearby. The specified radius can be any value.The radius may be configurable such as a user, administrator, or both.

Recent particle detections by other particle monitors may be defined asdetections occurring within a specified time window or duration from atime of the particle capture. The duration may be, for example, 12, 24,48, or more than 48 hours. The duration may be less than 12 hours. Theduration can be any value. The duration may be configurable such as by auser, administrator, or both. In an embodiment, the cloud servercalculates a duration between a time of particle capture by therequesting particle monitor and a time of particle capture by anotherparticle monitor. If the duration is less than the specified duration,the particle detections made by the other particle monitor may beconsidered relevant. If the duration is greater than the specifiedduration, the particle detections made by the other particle monitor maybe considered irrelevant.

If the degree of confidence does not exceed or is below the threshold,the particle monitor requests a review by a human technician (step3465). For example, the particle monitor issue the request to the cloudserver. Upon receiving the request, the cloud server may generate analert that is transmitted to the human technician. The alert mayinclude, for example, an email, text message, or other notification. Therequest from the particle monitor may include or be accompanied byimages of the captured particles that the particle monitor was unable toidentify with satisfaction.

It should be appreciated that the steps shown in FIG. 34 may occur in anorder different from what is shown. For example, in FIG. 34, obtainingcontext information (step 3455) is after capturing and analyzing thesecond image (steps 3440 and 3445). This is not necessarily, however,always the case. In another embodiment, context information be may beobtained before capturing and analyzing the second image.

For example, context information may be obtained and stored by theparticle monitor periodically such as at a specified time. The specifiedtime can be during off-peak hours such as nightly (e.g., 2:00 AM) whenthe network is less likely to be loaded. In this specific embodiment, atthe specified time, a particle monitor issues to a server a request forcontext information. The request is time-stamped and includes ageographical location of the particle monitor. The server receives therequest. Based on the time and geographical location of the particlemonitor, the server responds to the requesting particle monitor withrelevant context information. The particle monitor receives and storesthe relevant context information. The previous context informationstored at the particle monitor may be deleted, removed, or replaced withthe newly received context information.

The relevant context information may include current weather conditions,forecasted weather conditions (e.g., predicted weather conditions forthe next 12 hours, the next 24 hours, and so forth), pollen typescurrently in bloom based on the time and location of the requestingparticle monitor, pollen types expected or forecasted to be in bloombased on the time and location of the requesting particle monitor, alisting of particle types that have recently been identified by othernearby particle monitors, or combinations of these. Weather conditionsmay include wind speed, wind patterns, wind direction, humidity levels,temperature, chances of precipitation, precipitation activity,precipitation amounts, type of precipitation (e.g., drizzle, rain,sleet, hail, or snow), barometric pressure, and so forth.

Pre-fetching or caching the context information locally on a periodicbasis helps to ensure that the context information is up-to-date andavailable at the particle monitor when needed. Pre-fetching the contextinformation can help to increase the speed of particle analysis becausethe context information will be available from storage local to theparticle monitor. In other words, the context information is cachedlocally at the particle monitor.

Context information may be obtained according to a pre-determinedschedule. The pre-determined schedule can be hourly, twice-daily, daily,or any other frequency as desired. The schedule can be configurable suchas by a user, administrator, or both. Increasing the frequency at whichthe context information is pre-fetched and cached helps to ensure thatthe context information is up-to-date. However, frequent cachingincreases the number of connection requests that the server must serviceand consumes other resources such as network bandwidth. Factors toconsider in determining the frequency at which context information ispre-fetched include the rate at which the weather is expected to change,length of pollen blooming cycles, and other factors. In anotherembodiment, the context information is obtained on-demand.

In an embodiment, the particle monitor may capture any number of imagesof the particles to make an identification. This includes, for example,one, two, three, four, five, six, seven, eight, nine, ten, or more thanten images. In an embodiment, if a particle cannot be satisfactorilyidentified from a first image, the monitor may capture a second image ofthe particle. The conditions under which the second image was capturedmay be different from conditions under which the first image wascaptured.

The conditions may include differences in lighting or illuminationconditions (e.g., white light, infrared light, ultraviolet light, orquantum dot illumination), different focal lengths, different tapepositions, or combinations of these.

An analysis may be performed using three or more images comparedtogether or analyzed separately. An analysis may include comparing oneillumination source image to two different quantum dot wavelengthimages. Images may be captured in any order. For example, a first imageof a particle may be captured when the particle is illuminated with anillumination source not including quantum dots. A second image of theparticle may be captured when the particle is illuminated with aquantum-dot illumination source. The first image may be captured beforethe second image. The second image may be captured after the firstimage. The first image may be captured after the second image. Thesecond image may be captured before the first image.

In an embodiment, a method may include illuminating a particle withfirst light having a first emission spectra, capturing a first image ofthe particle illuminated with the first light, illuminating the particlewith second light having a second emission spectra; capturing a secondimage of the particle illuminated with the second light; illuminatingthe particle with third light having a third emission spectra; capturinga third image of the particle illuminated with the third light; andanalyzing the first, second, and third images to identify the particle,where the first emission spectra is different from the second and thirdemission spectra, and the second emission spectra is different from thefirst emission spectra. The second emission spectra may be from a firstset of quantum dots comprising size- or composition-tuned quantum dotstuned to emit the second emission spectra. The third emission spectramay be from a second set of quantum dots comprising size- orcomposition-tuned quantum dots tuned to emit the third emission spectra.The method may include analyzing at least one of the first, second, orthird images separately from another of the first, second, or thirdimages. The method may include comparing at least one of the first,second, or third images with another of the first, second, or thirdimages.

In an embodiment, a method includes imaging a particle, advancing acollection media (e.g., tape) having the particle slightly, and imagingthe same particle again. Optical image processing could then takeadvantage of this in several ways. Even if the tape only moves veryslightly, it is likely to randomize how camera pixels line up withfeatures of the particle, thus allowing the system to at least partiallyaverage out effects of discrete pixels on the image. Looking at the sameparticle from two sufficiently different directions enables the systemto apply the principles of binocular vision to obtain at least crudedepth or 3-D information. As discussed, particle height information maybe derived from the length of observed shadows with oblique lighting,and observing shadows from different directions will enrich the shadowinformation. All these techniques not only apply to pairs of images attwo tape advance locations, but also three or more images from three ormore tape advance locations.

In an embodiment, a method includes collecting particles onto acollection media; while the collection media is in a first position,capturing, via a camera sensor, a first image of a particle; moving thecollection media from the first position to a second position, differentfrom the first position; while the collection cartridge is in the secondposition, capturing, via the camera sensor, a second image of theparticle. In an embodiment, the illumination conditions under which thefirst image is generated are the same as the illumination conditionsunder which the second image is generated. In another embodiment, theillumination conditions under which the first image is generated isdifferent from the illumination conditions under which the second imageis generated. The moving of the collection media may be in a forward orreverse direction.

It should be appreciated that aspects and principles of the system maybe applied to analyzing a video of the particles that have beencollected. For example, in a specific embodiment, a particle monitorincludes a video recorder. The video recorder can record a single videorecording of the particles that have been collected. During therecording of the single video, the collection media upon which theparticles have been trapped may remain stationary and the particles maybe illuminated with a series of different lighting conditions (e.g.,white light, one or more different quantum-dot illumination sources,infrared light, or ultraviolet light). The system can then analyze thesingle video (e.g., single video file) to identify or discriminate theparticles. For example, one or more frames of the video may be analyzed.Alternatively, the collection media upon which the particles have beentrapped may move continuously during the entire recording or during atleast a portion of the recording. While the collection media is moving,the conditions under which the particles are illuminated may remain thesame or may change. An analysis may include analyzing both a still imageof a particle and a video recording of the particle.

FIG. 37 illustrates the contents of an exemplary particle informationpacket 3700 that may be generated by particle monitor 105 in anembodiment, in connection with analyzing particles captured by theparticle monitor. FIG. 38 shows a particle information packet history.

Referring now to FIG. 37, shown are parameters of a data structurestoring characteristics of a particle and metadata associated with theparticle. The data structure may be stored in the memory or storage of aphysical computing device. The data structure may be implemented, forexample, as a table of a database. While FIG. 37 shows some specificexamples of particle characteristics and metadata that may be collected,derived, and stored for a particle, it should be appreciated that therecan be instead or additionally other particle characteristics,associated metadata, or both that may be stored.

Consider, as an example, a particle monitor owned by a consumer with asevere allergic reaction to the pollen of spreading bent grass AgrostisStolonfera. In this context, FIG. 38 illustrates an example hypotheticalhistory of one particle information packet.

When a particle is observed in the field of view of the camera sensor ofthe consumer's particle monitor, a particle information packet 3700(FIG. 37) is created (step 3805—FIG. 38). At creation, it includes aparticle ID number 3712 (FIG. 37), a particle ID block 3720 containingitems 3721 through 3726, as well as an objectives block 3730 with anapplication type 3732 of “personal health” and a definition of particlesof interest 3734 of “Agrostis Stolonfera pollen.”

In the example shown in FIG. 37, the particle ID block includes atimestamp 3721, particle collection device serial number 3722, deviceGPS coordinates 3723, adhesive-coated tape reel number 3724,x-coordinate of particle along length of tape 3725, and y-coordinate ofthe particle (perpendicular to the length of tape) 3726.

In a specific embodiment, the particle identification subsystem includesa pixel-to-tape mapping unit that maps a location of a particularparticle that has been captured within an image to the particle'sphysical location on the tape. The mapping unit determines a firstlocation of a particle within an image. The first location may be a setof pixel coordinates. For example, a pixel coordinate X may representthe particle's location as measured along an x-axis from a referencepoint in the image. A pixel coordinate Y may represent the particle'slocation as measured along a y-axis from the reference point in theimage. The pixel coordinates can be mapped into real space or into realx-y coordinates as measured from a reference point on the tape.

The particle collection cartridges may be assigned unique serial numbersso that images of the particles can be associated with correspondingcollection cartridge having the physical particles. As discussed, in anembodiment, the particle monitor includes a counter that tracks aposition of the tape. For example, the counter may track an amount orlength of tape taken up by the uptake reel, an amount or length of tapeunspooled from the supply reel, or both. Tracking the position of thetape allows for cross-referencing the images with the correspondingphysical particles on the tape.

In another specific embodiment, the tape may include a set of markersthat can be captured in the particle images. The markers may beindividually or sequentially numbered and distributed at variousintervals along a length of the tape. An interval may correspond to awidth of a field of view of the camera sensor so that a markerassociated with the interval will be captured in an image. The markerallows for cross-referencing the image with the portion of tape wherethe corresponding physical particles have been trapped. The markings maybe made using any technique for making a visible impression on the tapeincluding, for example, printing, silkscreen printing, stamping, orchemical processing. Alternatively, the tape may include a magnitizablelayer for magnetic marking and readout of tape locations.

At this point, status block 3740 contains a measurement status flag 3742and an analysis status flag 3744 with no bits set, and nullwork-in-progress and definitive particle classifications 3746 and 3748.This is the state of particle information packet 3700 at step 3805 ofFIG. 38.

At step 3810 (FIG. 38), the particle monitor embedded software storesinto data block 3780 (FIG. 37) sensor data 3781 for those RBG camerapixels including and surrounding the detected particle. At this step, abit in measurement status flag 3742 is set to indicate the capture ofcamera sensor data 3781. At this point, no decision has been madewhether the detected particle is even a pollen grain rather than, forexample, a dust particle.

The first analysis step is step 3815 (FIG. 38). This first analysis stepinvolves estimating the diameter or longest major axis of the detectedparticle. From this measurement there results a work-in-progress orpreliminary particle classification 3746 (FIG. 37) such as “<5 microns”(less than 5 microns), “10-15 microns” (between 10 and 15 microns),“35-40 microns” (between 35 and 40 microns) or “>200 microns” (greaterthan 200 microns). A corresponding bit in the analysis status flag isset. If the result had been “<5 microns” (less than 5 microns) or “>200microns” (greater than 200 microns), a quick definitive particleclassification 3748 of “not Agrostis Stolonfera” would have been made onthe basis that the particle size is not compatible with the particles ofinterest 3734.

However, in this case we imagine a work-in-progress classification 3746of “25-30 microns” which is compatible with the particles of interest.However, this size range is also compatible with many particles that arenot of interest, such as dust particles that happen to be in this sizerange.

Given that the possibility remains that the packet might correspond to aparticle of interest, the software of the pollen monitor makes adecision to analyze particle shape. This is step 3820 of FIG. 38. If theoutcome had been “narrow rod,” or “spikey ellipsoid,” a definitive orfinal particle classification 3748 (FIG. 37) of “not AgrostisStolonfera” would have been made.

However, we imagine a resulting work-in-progress classification 3746 of“smooth ovoidal particle of 25-30 micron size.” In engineering practice,the work-in-progress classification 3748 can be a numerical code thatcan be configured, by for example, scientists and software engineers orother users. As with all analysis steps, another bit in the analysisstatus flag 3744 is set after completion of this analysis step.

The work-in-progress classification of “smooth ovoidal particle of 25-30micron size” does not exclude the possibility that the particle is apollen grain of Agrostis Stolonfera. As a result, in step 3825 (FIG.38), the pollen monitor's software makes a decision to analyze colorinformation in camera sensor data 3781 (FIG. 37). If the result had been“color of soot” or “color of dust,” the processing of the particleinformation packet 3700 would have ended with a “not AgrostisStolonfera” definitive classification 3748. However, to provide a moreinstructive example, imagine step 3825 (FIG. 38) results in awork-in-progress classification 3746 (FIG. 37) of “smooth ovoidalparticle of 25-30 micron size with pollen compatible color.”

Note that in steps 3820 (FIG. 38) and 3825, no new data is collected,only new analyses of previously measured data stored in data block 3780(FIG. 37).

At the completion of step 3825 (FIG. 38), the embedded software of theparticle detector has not yet reached a definitive classification, andmay not have the best information to decide what comes next. At such apoint, the particle detector looks for guidance from software on thecloud. In step 3830, the embedded software transmits the particleinformation packet 3700 (FIG. 37) to the cloud.

The cloud software has access to great deal more information than doesthe embedded software of the particle monitor. For example, the cloudsoftware may have access to databases where the system collects andstores relevant information such weather patterns, elevations at variousGPS coordinates, historical records of past pollen seasons, as well aswhich plants are currently producing pollen in which geographical areas.The pollination season for Agrostis Stolonfera is sometime in the springthrough fall depending on the elevation and latitude corresponding tothe device GPS coordinates 3723 (FIG. 37) of particle identificationblock 3720. For example, if time stamp 3721 corresponds to the middle ofwinter, the presence of Agrostis Stolonfera can be excluded. However, inFIG. 38 we consider the case that the contextual information availableon the cloud does not exclude detection of particles of interest 3734(FIG. 37).

To provide better discrimination between types of pollen, the cloudsoftware may decide that better morphology information is desirable andin step 3840 (FIG. 38) sends a request to the particle monitor tocollect further camera images of the pollen with one or more alternatefocal depths. Focal depth may be varied by mechanical movement of lensand/or camera sensor, by electronic control of a variable lens, bysoftware control of processing of image data from a light-field camerasystem, or combinations of these.

The request received by the particle monitor triggers step 3845 and therequested measurement are made and added to the alternate focus data3782 (FIG. 37) of data block 3780. With this additional data, in step3850, a more refined shape or morphology analysis is performed. Theanalysis of step 3850 may be performed by embedded software of theparticle monitor (e.g., analyzed locally at the particle monitor), bycloud software (e.g., analyzed remotely by a cloud server), or both.

By capturing images of a pollen grain (or other particle) at multiplefocal depths, all parts of a pollen grain can be brought into focus,thus providing more complete morphological information. For translucentpollen grains, a scan of focal depth may be used to capturethree-dimensional pollen structure information.

In step 3855, the cloud software also sends a request to the particlemonitor to collect further camera images with an alternate illuminationsource. In step 3860 the alternate illumination data is stored as item3783 (FIG. 37) in data block 3780.

Here we assume that the pollen monitor is equipped with a quantum-dotLED illumination source tuned to the red absorption line ofchlorophyll-a. As discussed above, a distinguishing characteristic ofgrass pollen is the presence of a chlorophyll color signature. Thequantum-dot LED illumination source may be optional hardware that wasincluded in the particle monitor configuration due to the consumer'ssensitivity to grass pollen; in this sense the definition of particlesof interest 3734 may not only influence processing of a particleinformation packet 3700, but also influence the hardware configurationof the particle monitor. Let us assume that such a chlorophyll sensitivealternate illumination is used and in step 3865 (FIG. 38), analysis(local, on the cloud, or both) of all the color data in block 3780 (FIG.37) confirms the presence of chlorophyll.

At this point, the evidence is strong that the detected particle is agrain of Agrostis Stolonfera pollen. However, before disturbing theconsumer with an alert, it may be prudent to obtain a second opinionfrom a human technician. In the scenario of FIG. 38, the cloud softwaresends a request for a second opinion from a trained technician. In step3875, resulting technician notes are stored in data block item 3787(FIG. 37). The request may include particle data collected by the systemand the system's determination of the type of pollen based on theparticle data. This information may be displayed, for example, on anelectronic screen such as via a web page provided by the system. The webpage is accessible by the trained technician. The web page may furtherinclude an input box that the technician can use to enter notesregarding the accuracy of the identification and other information.

The technician may in turn request a third opinion by a scientificspecialist whose notes are captured in step 3880. In this scenario, weimagine that the scientific specialist is fully convinced and “AgrostisStolonfera” becomes the definitive particle classification 3748 (FIG.37). It is now time to inform the consumer that allergenic pollen hasbeen detected (step 3885).

In the interests of cost and a fast response, it may well be moreexceptional than routine to involve humans, as in steps 3875 and 3880,in which it is otherwise an automated particle (e.g., pollen or moldspore) detection and classification system. This exceptional scenario isconsidered here to more fully describe a deeply multi-tiered pollendiscrimination scenario. A deeply multi-tiered scenario may also be onewhere the user of a particle monitoring device has required human reviewof the particle data every so often (e.g., periodically). An example ofthis is an institutional, commercial, or single user with multiplesystems deployed across a region and operating 24 hours a day 7 days aweek. In such a scenario, human involvement as described in steps 3875and 3880 may take place as part of a quality assurance procedure.

For example, a human review of particle data may be required after onehundred, one thousand, ten thousand, a million, or another number ofparticle detections have occurred. A human review of particle data maybe required every hour, once a day, once a week, once a month or at someother interval of time. The criteria or frequency for when human reviewof particle data is required can be configurable such as by a user oradministrator of the system. The system (e.g., pollen monitor, pollencloud server, or both) can track this criteria to determine when a humanreview of particle data is required. When a human review of particledata is required, the system can send out a notification to the humanreviewer to request a review of the particle data. The request mayinclude the particle data and a pollen identification made based on theparticle data. The human reviewer can review the particle data to seewhether or not the pollen or other particle identification was correct.Further leveraging of the talents of the human reviewer may be providedby using results of human reviews as input to automated machine learningalgorithms so that reliance on human review decreases with time.

In a specific embodiment, a feature of the system includes providingconsumers or customers of the system with human interaction or a humantouch. Rather than just an automated text message alert, in some cases aphone call with follow-up questions such as “How are you feeling?” froma customer service specialist of the system or perhaps the consumer'sdoctor may be well appreciated, add value and create loyalty.

Even after the consumer has been alerted, the particle informationpacket may continue to be processed for quality control and algorithmdevelopment purposes. In step 3890, the used reel of adhesive-coatedtape containing the detected particle is collected and stored in anarchive. Later, in step 3895, a bioassay using anti-bodies specific tothe troublesome antigens of Agrostis Stolonfera is performed to verifybeyond a shadow of a doubt that the particle was correctly classified—orto learn that a mistake was made and that the particle informationpacket should be closely studied to determine what changes need to bemade to the algorithms of the various tiers of the pollen discriminationsystem. Depending on a particle information packet's history, the datablock 3780 may also contain information from the cloud on local weatherconditions 3785, information from the cloud on known seasonal allergensand pathogens 3786, laboratory microscope images 3789 of archivedparticles, bio-assay data 3790, expert-technician notes 3791 and/orexpert scientist notes 3792.

FIG. 39A shows a flow of a process for associating an image of thecollected particles with their corresponding location on the adhesivecoated tape. In a step 3910, particle monitor 105, in an embodiment,advances the tape to place a portion of the tape having the collectedparticles within a field of view of the camera sensor. In a step 3915,the particle monitor tracks a position of the tape corresponding to theplacement. For example, the position of the tape may be measured along alength of the tape between a reference point and the position. Thereference point may be, for example, a beginning of the tape, an endingof the tape, or any arbitrary reference point along the tape.

In a step 3920, an image of the portion is captured. In a step 3925, theposition of the tape at which the image was taken is associated with theimage. In a step 3930, the image and tape position is stored. Forexample, the image may be tagged with the position of the tape. Theposition of the tape may be stored as metadata associated with theimage.

Storing the position of the tape at which the image was taken allowsthat particular portion of the tape having the actual physical particlesto be later accessed. For example, the tape may be mailed to alaboratory for further analysis. The tape position information may bereferred to as an address. Table H below shows an example of metadatainformation that may be stored, such as within an image index, thatcross references an image of particles with a portion of the adhesivecoated tape at which the physical particles are located.

TABLE H Image ID Cartridge ID Location (mm) image001 cartidge001 500image002 cartidge001 800 . . . . . . . . .

In the example in table H above, a first column stores an identifierthat uniquely identifies the image. A second column stores an identifierthat uniquely identifies the cartridge. A third column stores a locationon the tape of the cartridge that maps to a position of the tape atwhich the image was taken. In a specific embodiment, location may be adistance measurement. The distance may be measured along a length of thetape from a beginning (or ending) of the tape. For example, a first rowof the table includes the location value “500 mm” for “image001.” Thiscan indicate, for example, that an edge of the image corresponds to alocation on the tape that is 500 mm from a beginning end of the tape.The location on the tape can correspond to an edge of a field of viewwithin which the image was taken.

FIG. 39B shows a flow of a process for server-aided particleidentification or discrimination. In a step 3950, the particle monitorcaptures a first image of particles collected by the particle monitor.

In a step 3955, the particle monitor transmits to the server dataassociated with the first image. The data may be from a preliminaryanalysis performed by the particle monitor on the first image. Thepreliminary analysis may include, for example, a morphology analysis. Ina specific embodiment, rather than sending the actual first image to theserver, the particle monitor sends a smaller packet of information tothe server as image files can be quite large (e.g., several megabytes insize). Reducing the amount of data that is sent over the network helpsto conserve network bandwidth.

In another specific embodiment, the particle monitor may send a portionof the first image, rather than the entire first image. For example, theparticle monitor may perform a preliminary analysis in which theparticle monitor identifies a portion of the image as containing aparticle. Other portions of the image may not include particles or mayinclude particles that the particle monitor quickly concludes are not ofinterest. The portion of the first image having the particle may becropped, thus reducing the file size. In another specific embodiment,the particle monitor may transmit the entire first image to the server.

Determining the amount of data to send can be based on a degree ofconfidence in a preliminary assessment of the captured particles. Theamount of data that is transmitted by the particle monitor to the servercan vary inversely with the degree of confidence in the preliminaryassessment. In other words, when the particle monitor calculates a highdegree of confidence in the preliminary assessment (e.g., degree ofconfidence is above a threshold), less data may be transmitted to theserver (e.g., portion of first image). When the particle monitorcalculates a low degree of confidence in the preliminary assessment(e.g., degree of confidence is below the threshold), more data may betransmitted to the server (e.g., the entire first image).

In a step 3960, the server receives the data from the particle monitorand processes the data. The server generally has access to morecomputing resources than the particle monitor. Such resources mayinclude more powerful processors, more storage capacity, and the like.The additional computing resources allow the server to executeidentification algorithms that might otherwise crash the particlemonitor when executed on the particle monitor. The server may execute,for example, a more complex image recognition algorithm in order toidentify the particles. Performing at least some of the analysis on theserver also helps to conserve the limited battery supply of the particlemonitor.

In a step 3965, based on the server-side processing of the receiveddata, the server issues to the particle monitor instructions forcapturing a second image of the collected particles. The instructionsmay include, for example, a specification of the conditions under whichthe particles are to be illuminated (e.g., illuminate under UV light,illuminate under IR light, illuminate under red light, illuminate underblue light, and so forth), a specification of the focal length, tapepositioning information, or combinations of these.

The tape positioning information may instruct the particle monitor toadvance the tape forward by a certain amount or rewind the tapebackwards by a certain amount. For example, the first image may havecaptured a portion of particle whereas a remaining portion of theparticle may have been outside the field of view of the camera sensor.In this case, the tape may be advanced forward or backward so that theremaining portion of the particle may be brought into the field of viewfor the second image.

FIGS. 40-43 show various views of particle monitor device 4005 accordingto another specific embodiment. The particle monitoring device samplesambient air, captures particles (e.g., pollen or mold spores) on anadhesive-coated tape, images captured particles with a camera lens andcamera sensor, and archives adhesive coated tape with captured particleson a take-up reel.

Camera-image data and the results of its analysis may be stored orlogged for later use. Likewise, physical samples of pollen and otherparticles may be stored or archived for possible later retrieval. FIG.40 shows a side view of the collection device in a Y-Z plane. FIG. 41shows a side view of the collection device in an X-Z plane. FIG. 42shows a plan view of the collection device. FIG. 43 shows another planview of the collection device.

Referring now to FIG. 40, this particle collection device includes acylindrical enclosure, cabinet, or housing 4003 having a set of intakevent holes 4006 and a set of outtake or exhaust vent holes 4009. Theintake vents are located on a side surface of the enclosure between atop end of the enclosure and a bottom end of the enclosure, opposite thetop end. The intake vents are positioned closer to the top of theenclosure than the bottom. The outtake vents are at the top of theenclosure.

Internal components include a duct 4012 connected between the intake andouttake vents, a blower 4015 positioned inside the duct, a firstconveyor assembly 4018 below the duct, a second conveyor assembly 4021below the first conveyor assembly, an optical microscope 4105 (FIG. 41),electronics 4024 (e.g., processor or network interface card), and apower source (e.g., battery) 4027. The power source and electronics arehoused at the bottom of the enclosure. The power source supplies powerto the blower, conveyor assemblies, optical microscope, and otherelectrical components of the collection device.

The duct includes a horizontal segment 4030 and a vertical segment 4033.In the example shown in FIG. 40, a bottom end of the vertical segment isconnected to a middle portion of the horizontal segment. The verticalsegment extends along a central or longitudinal axis of the enclosure.The horizontal segment is orthogonal to the vertical segment. The intakevents open into the horizontal segment of the duct. The outtake ventsare at a top of the vertical segment of the duct. A bottom portion ofthe horizontal segment includes an opening 4036 between opposite intakevents.

First conveyor assembly 4018 includes rollers 4039A, B, C, and D, and anon-stick tape 4042 (see FIG. 42). A roller may be referred to as apulley or drum. The non-stick tape passes around rollers 4039A, B, and Cand above roller 4039D. Roller 4039D is controlled by a stepper motor(indicated the figure by a pattern of vertical lines) and is coated witha sticky adhesive. Via roller 4039D, the stepper motor controls themotion of the non-stick tape so that it moves in a direction asindicated by an arrow 4045. A portion of the non-stick tape is exposedthrough opening 4036. Roller 4039C is provided with a vibrator ormechanism to vibrate at acoustic or ultrasonic frequencies (indicated inthe figure by a pattern of horizontal lines).

Second conveyor assembly 4021 is below the first conveyor assembly andis oriented orthogonally to the first conveyor assembly. Second conveyorassembly 4021 (as shown in FIG. 41) includes rollers 4110A and B, reels4115A and B, and an adhesive coated tape 4120. The adhesive coated tapeis supplied by reel 4115A, passes around or is guided by rollers 4110Aand B, and is collected by reel 4115B. A motion 4125 of the adhesivecoated tape is driven via take-up reel 4115B by a second stepper motoras indicated in the figure by a pattern of vertical lines.

The optical microscope includes an optical column 4130 with objectivelens array 4135 and a camera-image sensor 4143.

Referring now to FIG. 40, blower 4015 drives a flow of air into theintake vents and out the outtake vents. More specifically, arrows4050A-D indicate the flow of sampled ambient air, perhaps containingpollen and other allergenic substances, into the device via the intakevent holes. Vertical walls 4053 (see FIG. 42) and horizontal ceiling4056 of the duct help channel the incoming air in desired directions.The airflow is driven by the blower. The blower also drives downstreamairflow indicated by arrows 4140A-D (FIG. 41). Air exits the device viathe outtake vent holes.

The non-stick tape may include a loop of Teflon™ or other materialgenerally regarded as a non-stick material and completes the boundariesfor the incoming air flow. The tape forms a loop and may be referred toas a non-stick tape loop. The tape may be, for example, a polymer tapeor include a polymer material. Other appropriate materials may insteador additionally be used. Despite use of a tape material generallyregarded as non-stick, very small particles such as pollen grains willstick to the surface of the non-stick tape loop as a result of Van derWaals forces. In alternate embodiments, the non-stick tape need not be aloop, but rather can be tape supplied reel to reel for one-time use. Inother specific embodiments, the non-stick tape may be cleaned after useso that it can be reused one or more times.

As shown in the example of FIG. 40, at least a portion of the non-sticktape loop is positioned so that it is near airflow 4050A-D. For example,the at least a portion of the non-stick tape may be below the airflow ormay be within or at least partially obstruct the airflow. In a specificembodiment, at least a portion of the airflow path passes over opening4036 of the duct through which at least a portion of the non-stick tapeloop is exposed. Due to the force of gravity, particles such as pollengrains (e.g., pollen grains 4060A-C) will settle out of the sampledambient air in the airflow and stick to the surface of the non-sticktape loop that is exposed through the duct opening. When desired, thenon-stick tape loop is moved in the direction indicated by arrow 4045.This illustrates the use of gravity to separate particles such as pollengrains from ambient air.

As discussed above, the loop is supported by rollers 4039A and 4039B.Roller 4039D is controlled by a stepper motor (not shown) and is coatedwith a sticky adhesive. Via roller 4039D, the stepper motor controlsmotion 4045 of the non-stick tape loop. Roller 4039C is provided with amechanism to vibrate at acoustic or ultrasonic frequencies. This resultsin at least some of the captured particles such as pollen grains (e.g.,pollen grains 4065A-B) being released under the influence of gravity.Due to its sticky adhesive, roller 4039D will remove any pollen andother particles on the surface of the non-stick tape loop that were notremoved by vibration of roller 4039C.

Referring now to FIG. 41, vibration released pollen grains 4065A and4065B fall and land upon adhesive coated tape 4120. As discussed, theadhesive coated tape is supplied by reel 4115A, is guided by rollers4110A-B and is collected by reel 4115B. The motion of theadhesive-coated tape is driven via take-up reel 4115B by a secondstepper motor (not shown). Motion 4125 of the adhesive-coated tape movescaptured particles such as pollen grain 4065B′, within a field of view4145 of the optical microscope.

The optimal or desired field of view will depend on the application. Ina specific embodiment, a field of view of width is about 1 millimeter(mm). In a specific embodiment, a width of the field of view issubstantially narrower or less than the width of the pollen (orparticle) collection region of non-stick tape 4042, advantageouslygreatly increasing the concentration of particles in the field of view.For example, a ratio between the field of view of width and the width ofthe pollen collection region of the non-stick tape may be about 1:2. Inother specific embodiments, the ratio may be about 1:1.2, 1:1.4, 1:1.6,1:1.8, 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or1:10.

In a specific embodiment, the exposed horizontal surface area of thenon-stick tape loop is about 7 centimeters (cm)×2 cm=14 cm{circumflexover ( )}2. For smaller particles (e.g., pollen or mold spores) ofdiameters of about 20 microns, the particle settling rate is roughly 1cm/second, resulting in an air sampling rate of about 14 cm{circumflexover ( )}2×1 cm/sec=14 cm{circumflex over ( )}3/sec=840 cm{circumflexover ( )}3/minute=0.84 liter/minute. This is the case if the blowerestablishes sufficient airflow so that air reaching the most interiorportions of the non-stick tape loop are depositing particles, e.g.,pollen grains. This is about one order of magnitude less than a typicalbreathing rate of a resting human. In some applications this may besufficient. In other applications, it will be desirable to increase theambient-air sampling rate. Particularly for indoor applications, therelatively fast settling of particles such as pollen out of air and therelatively low “wind velocity” indoors may well vary by orders ofmagnitude from one location to another within a home. Intelligentplacement of one or more particle monitors within a home may wellprovide a desired order of magnitude increase in effective pollenmonitor sensitivity.

In many cases, the two stepper motors may be at rest most of the time.For example, the non-stick tape loop may be at rest for one minute whileparticles such as pollen grains (e.g., pollen grains 4060A-C) accumulateon its surface. After a sufficient such period, the stepper motordriving roller 4039D may be activated and ultrasonic release roller4039C may be excited for sufficient time to transfer all or at leastsome of the collected pollen grains onto the adhesive-coated tape (see,e.g., falling grains 4065A-B). Roller 4039D cleans the non-stick polymerloop material in preparation for a subsequent sampling period. Forexample, the roller may include a brush to clean the non-stick tape ofparticles. The operation of the stepper motors may be triggered basedupon a pre-determined schedule or frequency. Instead or additionally,the operation of the stepper motors may be triggered based on some otherevent.

As a result, particles such as pollen sampled from 840 cm{circumflexover ( )}3 of ambient air is deposited in a narrow strip belowultrasonic release roller 4039C and onto the adhesive-coated tape.Ideally the width of these deposited particles (e.g., pollen grains) isno wider than the field of view of camera image sensor 4143 (FIG. 41) sothat all particles (e.g., pollen) collected may be imaged. After thetransfer of particles from the non-stick tape loop to theadhesive-coated tape is complete, then via reel 4115B the second steppermotor may move the collected pollen through the field of view of themicroscope system.

In a specific embodiment, an operation of the collection device istriggered upon a determination that the user has suffered an allergicreaction. In this specific embodiment, the collection device receives arequest (such as from the analysis server or allergic reactionmonitoring device with sensor) to sample the ambient air. Upon receivingthe request, the blower is activated. Particles within the airflowsuction or vacuum caused by the blower are deposited via gravity throughthe bottom opening of the duct and onto the waiting non-stick tape ofthe first conveyor assembly.

Once the period of collection is complete, the non-stick tape may beadvanced. When the portion of the non-stick tape having the collectedparticles reaches roller 4039C, the advancement of the non-stick tapemay be paused or slowed while roller 4039C is vibrated to shake thecollected particles off and onto the adhesive-coated tape of the secondconveyor assembly. Once the shaking is complete, the adhesive-coatedtape may be advanced.

When the portion of the adhesive-coated tape having the collectedparticles reaches or is within the field of view of the camera sensor,the advancement may be paused or slowed so that the camera sensor cancapture an image of the particles stuck to the adhesive-coated tape. Thecaptured images are then analyzed to identify the captured particles(e.g., pollen).

A combination of factors including pollen optical properties (e.g., blueto red ratio) and pollen grain size may be evaluated using an algorithmof the system to identify pollen. Pollen grain size can be determinedaccording to scattered light intensity. For example, pollen such asragweed, Japanese cedar, walnut, and kamogaya may be identified based ontheir respective blue/red fluorescent light ratios and pollen grainsizes. Any competent technique or combinations of techniques may be usedto automatically recognize or identify the collected pollen. Someexamples of identification techniques include image processing,non-image optical properties such scattering and fluorescence, andothers.

The operations of the system, such as the collection operations, can belogged and time-stamped. The time-stamping allows for across-referencing of the collected particles (and particleidentifications) with the time of the allergic reaction. As one of skillin the art will recognize, the rate at which the conveyor assembliesadvance their respective tapes can be synchronized or sequenced with thecamera sensor so that the tape portion having the collected particles isproperly positioned with respect to the camera sensor for imaging.

In a specific embodiment, the adhesive coated tape having the collectedphysical particles is archived and retained for possible futureretrieval. The reel of tape can be removed from the particle collectiondevice and sent to a laboratory for archiving and further analysis.

In a specific embodiment, a number of the intake vents or orifices andthe incoming air can be as little as a single orifice or there can bemultiple intake vents (e.g., two or more). In an embodiment having asingle intake vent, it can be desirable (but not required) for thedevice to have a mechanism for aligning itself in the direction ofincoming wind in order to sample as many particles flying through theair as possible or desired. For example, the mechanism may include windvane to identify a direction of the wind. Once the direction of the windis identified, the collection device may then automatically rotate ororient itself so that the intake orifice is aligned with the incomingwind.

In another specific embodiment, there are many or multiple intakeorifices to cover the entire circumference (or a portion of thecircumference) of the cylindrical device. In this specific embodiment,aligning the device in the direction of oncoming wind may not benecessary.

FIG. 40 shows a dimension D16 that indicates a diameter of thecollection device and a dimension H16 that indicates a height of thecollection device. In a specific embodiment, the diameter is about 100mm and the height is about 150 mm. It should be appreciated, however,that these dimensions may vary greatly depending upon factors such asdesired performance criteria, manufacturing cost targets, expectedservice life, expected operating environment, and many others. Acylindrical shape is preferred but not required. For example, inaddition to providing an aesthetic appearance, a cylindrical monitorwith a vertical axis of rotation can rotate to sample pollen fromdifferent orientations without risk of mechanical interference. Anyshape or form factor may be suitable as long as there is an intakeorifice in any orientation where the particles can be separated andanalyzed as described by the mechanisms and techniques herein.

The air intake orifices or duct can be made to vibrate and oscillate tovarious frequencies such that particles that may have attached to theorifice or duct surface can separate from the surface and the air intakepull force will pull these in towards the surface of the non-stick tape.

In a specific embodiment, the adhesive-coated tape is transparent. Thisallows the optical imaging elements to be placed on a backside of thetape (i.e., a side of the tape opposite a side having the collectedparticles) and still be able to capture an image of the particles foranalysis. There can be many different configurations of the particlecollection device to meet desired form factors, performance, and soforth. Thus, it should be appreciated that the mechanical schematicsshown in FIGS. 40-43 are merely an example of one particularimplementation of the collection device.

In other implementations, other similar and equivalent elements andfunctions may be used or substituted in place of what is shown. Forexample, roller 4039C of the first conveyor assembly is shown as beingaligned along a centerline or longitudinal axis of the collectiondevice. The roller, however, may be offset from the centerline or closerone side of the collection device than an opposite side of thecollection device so long as the adhesive-coated tape of the secondconveyor assembly is suitably located to collect the particles whichfall from the non-stick tape of the first conveyor assembly.

As another example, a vibration mechanism has been described as atechnique to transfer particles from the non-stick tape of the firstconveyor assembly to the adhesive-coated tape of the second conveyorassembly. In another specific embodiment, however, a vacuum, brush, orboth may instead or additionally be used to transfer the particles. Asanother example, the optical imaging elements (e.g., camera sensor) maybe configured to capture images of the particles while the particlesremain on the non-stick tape.

In another specific embodiment, there is a particle monitoring devicethat creates an electromagnetic field to push and pull particles asdesired by having a roller made of an electrically conductive materialserving as one electrode and a second electrode (not shown) placeddirectly underneath adhesive coated tape, and voltage applied across thetwo electrodes. This provides an electric field where particlesproximate to roller move on to adhesive coated tape. It can alsofunction in an alternating field where the roller and adhesive coatedtape change polarity allowing the use of non-conductive materials fornon-stick tape loop and adhesive coated tape as well as forcingparticles that are negative or positive be expelled from the roller ontothe adhesive coated tape.

Some of the above variations of the particle monitoring system areillustrated by device 4400 of FIGS. 44-47. While device 4005 of FIGS.40-43 is well-suited for environments with gentle airflow such asindoors, device 4400 of FIGS. 44-47 is well-suited for outdoor use whereit may be desirable to collect particles such as pollen when there isambient airflow due to the wind. FIG. 44 illustrates the case that inputvent hole 4414 is a single hole. A swivel mount 4470 is schematicallyillustrated which allows device 4400 to rotate so that the input venthole 4414 faces the wind. The orientation mechanism may be passive suchas due to vanes (not shown) on the exterior of enclosure 4410 or activesuch as a stepper motor incorporated into swivel mount 4470 that iscontrolled by battery powered electronics 4480 that is provided withwind direction data.

While device 4400 may include a fan or blower to control airflow, FIG.44 illustrates the case that airflow is wind powered. Wind pressure willnaturally drive airflow 4412 from input vent hole 4414 to output venthole 4415. An electronically controlled shutter 4417 in front of outputvent hole 4415 may partially cover or extend over the output vent hole4415 and thus control the rate of airflow 4412. Input vent hole 4414 maylikewise be provided with a similar shutter (not shown). A horizontalceiling and vertical walls (not shown) similar to items 4056 and 4053 ofdevice 4005 of FIG. 40 confine airflow 4412 as desired. Due to theinfluence of gravity, particles 4426, such as pollen grains, will settleout of the sampled ambient air and stick to non-stick tape loop 4430that wraps around rollers 4432 and 4433. Up to this point the particlecollection mechanism of device 4400 is very similar to that of device4005.

Device 4400 also makes use of an adhesive coated tape 4440 similar toadhesive coated tape 4120 of device 4005. However, device 4400illustrates a very different mechanism for transferring collectedparticles from non-stick tape to adhesive coated tape. When plunger 4560(FIG. 45) is activated (by a mechanism that is not shown), it pressesthe adhesive surface of adhesive coated tape 4440 (FIG. 44) againstnon-stick tape loop 4430 so that particles on non-stick tape loop 4430make contact with the adhesive of adhesive coated tape 4440. Whenplunger 4560 (FIG. 45) is retracted, the adhesive coated tape 4440 (FIG.44) moves away from the non-stick tape loop 4430 bringing particles 4538(FIG. 45) with it. During this particle transfer cycle, the non-sticktape loop 4430 (FIG. 44) is supported by roller 4433 in a way thatprovides for a contact area between the two tapes whose width is matchedwith the width of the field of view of an optical microscope systemcomprised of an optical column 4652 (FIG. 46), an objective lens array4654 and a camera-image sensor 4656.

As illustrated in FIG. 44, the non-stick tape loop 4430 is guided byrollers 4432 and 4433, one of which is controlled by a first steppermotor. Additional rollers may be added if desired. Optionally roller4433 may be provided with a vibration mechanism that is not strongenough to overcome Van der Waals forces for particles of interest suchas pollen, but still sufficient to shake off larger particles, objectsthat are not of interest, or both. A further mechanism (not shown) forremoving larger particles that are not of interest is to include asnow-plow like blade above the non-stick tape loop as it passes aroundroller 4433 and before it reaches the transfer region.

FIG. 44 also illustrates the option for the particle collection surfaceof non-stick tape loop 4430 to deviate from a perfectly horizontalorientation. This enables the region of transfer between the two tapesto be tilted as shown and as necessary to fit all components of thedevice 4400 within enclosure 4410. The needs of mechanically packing allcomponents within enclosure 4410 also motivates a more involved path foradhesive coated tape 4440 relative to the path in device 4005 foradhesive coated tape 4120. Other than being tilted, supply reel 4442 androller 4444 is similar to reel 4115A and roller 4115B of device 4005.After collecting particles 4538 (FIG. 45), adhesive coated tape 4440passes over roller 4445 and twists to roller 4446 so that the adhesivefaces outward and downward by the time it reaches roller 4447. Betweenroller 4447 and 4448, the adhesive coated tape 4440 moves through thefield of view of the optical system so that particles such as particle4450 (FIG. 47) may be imaged. After leaving roller 4448, the adhesivecoated tape is collected by reel 4443. Reel 4443 is driven by a secondstepper motor when desired so that the adhesive coated tape 4440 movesin the direction indicated by the arrow 241.

The optical microscope system comprised of optical column 4652,objective lens array 4654, and camera-image sensor 4656 is similar tothe optical system of device 4005 of FIGS. 40-43 with two exceptions.First, the axis of the optical column is now tilted rather than beingvertical as illustrated in FIG. 41 for optical column 4130. Secondly,imaged particle 4450, and the adhesive that holds it, is on the backsideof the adhesive coated tape 4440 from the perspective of the opticalsystem. This requires adhesive coated tape 4440 to be transparent.

Many variations of hardware designs may support the steps of the flowchart of FIG. 33. FIGS. 48 and 49 correspond to a contrasting example.FIGS. 48 and 49 are two perspectives on the same example device. As wewill see in the next example, the steps of the above flow chart are notlimited to automated pollen detection systems based on RGB camerasensors.

FIGS. 48 and 49 illustrate a pollen monitoring system without an RGBcamera sensor. FIG. 48 shows a top view of the pollen monitoring system.FIG. 49 shows a front view of the pollen monitoring system. In aspecific embodiment, the pollen monitoring system may be referred to asa tree pollen monitor or simplified pollen monitor.

The pollen monitoring system of FIGS. 48-49 may be installed in thebranches of a tree that is known to produce allergenic pollen and isknown to do so with a seasonal timing representative of similar trees inthe neighborhood. When such a monitoring system of FIGS. 48-49 detects ahigh concentration of particulates, it may be sufficient to simplydistinguish between pollen and other particulates and assume that whenpollen is detected in high concentration in the appropriate season, thedetected pollen is from the tree the monitoring system is mounted in.

As discussed above, tree leaves are green because their chlorophyllstrongly absorbs red and blue light; see the chlorophyll-a absorptionspectrum shown in FIG. 22. In particular, see the strong red absorptionpeak 2210 around 665 nm wavelength. The width of this absorption peak israther similar to the width of quantum dot emission spectra. Thisimplies that the tree leaves will be particularly effective in shadingsunshine and ambient light within the spectrum of a 665 nm redquantum-dot light source. The pollen monitor of FIGS. 48-49 takesadvantage of this observation.

FIGS. 48-49 illustrate a pollen monitoring system within an opaqueenclosure 4830 through which passes a tube 4840 that is transparent forred around 665 nm and largely opaque at other wavelengths. Such a systemis only susceptible to ambient light for a narrow range of wavelengthsaround 665 nm. When installed within the shade of green tree leaves,ambient light in that spectral range is greatly reduced due tochlorophyll light absorption. Furthermore, standard ambient lightsubtraction techniques based on capturing optical signals with both theillumination source 4870 on and off may further suppress ambient lightbackgrounds. All of this allows for a relatively open airflow system(driven by fan 4850 at downstream end of tube) that beneficiallyminimizes or reduces surfaces for pollen to stick to before reaching theoptical detection zone.

The sensors 4860 shown in FIG. 48-49 may simply be phototransistors.With sensors 4860, scattering is observed at both small angle and largeangle (90 degree) scattering. Light beam 4875 (FIG. 49) from LED 4870(e.g., quantum dot LED) may pass through a pollen grain 4980 resultingin light scattered at a small angle and detected by a sensor 4860, as inlight beam 4990, as well as light scattered at a large angle anddetected by a sensor 4860 as in light beam 4995. Smaller particles tendto have a larger ratio of large angle scattering light to small anglescattered light. Larger and more dense particles tend to scatter morelight. This provides means to estimate particle size and density; insome applications this may be enough to discriminate between tree pollenand other particulates.

The pollen monitoring system of FIGS. 48-49 may be modified to takeadvantage of the second chlorophyll-a absorption peak 2220 (FIG. 22) forblue light around 465 nm. As with 665 nm red peak 2210, tree leaves arevery black for such light around 465 nm thus suppressing sunshine andother ambient light in this spectral range. Instead of just oneillumination source 4870 to provide narrow spectrum 665 nm red light viaquantum dots, a second quantum-dot LED illumination source (not shown)at 465 nm may also be provided. In this case the tube 4840 that isgenerally opaque would be designed to be transparent around both 465 nmand 665 nm. Optionally, the scattered red and blue light is detected byseparate sets of sensors. Alternatively the same sensors detect bothlight colors. A further design option is to allow tube 4840 to betransparent at all wavelengths (e.g. a simple plastic or glass tube)while locally providing each sensor with an optical filter that passesonly the desired narrow range of wavelengths around 665 nm and/or 465nm. With both red and blue light scattering information, colorcharacteristics of pollen is obtained and discriminating power isincreased.

The flow chart of FIG. 33 also applies to the simplified pollenmonitoring system of FIGS. 48-49. Ambient air is sampled and transporteddown the tube 4840 to an illumination zone associated with sensors 4860and illumination source 4870; this illustrates steps 3310 and 3320 inFIG. 33. The 665 nm red LED 4870 may be selected by a localmicroprocessor program, the LED then excited and signals from thesensors collected per steps 3330, 3340 and 3350. Optionally, if thehardware is designed to also support 465 nm blue illumination and signalcapture, steps 3330, 3340 and 3350 may be repeated for the blueillumination. While not shown, a local microprocessor may analyze thecollected optical data (step 3360) and transmit it wirelessly to thecloud (step 3370). Devices such as that illustrated in FIGS. 48-49 maybe employed to provide the cloud with up-to-date information on bloomingtrees dispersing allergenic pollen, so that such information isavailable to the cloud at step 3455 of the flow of FIG. 34.

In some pollen monitoring system designs, it may be possible to wellisolate the optical detection zone from ambient light. In otherparticular monitoring systems it may be desirable to minimize or reducethe obstacles in the path of airflow carrying pollen or otherparticulates to the optical detection zone. While this may improvepollen and particular transport and sampling efficiency, such a designapproach makes it more difficult to eliminate ambient light backgroundsat the optical detection zone. As a general observation for suchsituations, the narrow spectrum feature of quantum-dot illuminationsources provides an ambient-light suppression benefit in allowingnarrow-spectrum filters to be placed between sources of ambient lightand optical sensors of a pollen monitoring system. The system of FIGS.48-49 is just one specific example of this general principle.

In alternate embodiments, different approaches are taken for air intakehardware 220 (FIG. 2) and particle capture hardware 222. While in someof the embodiments described above, turbulent airflow was preferred inthe particle capture zone, in alternate embodiments, gravitationalsettling of particles out of air are may be used to separate samplesparticles from the ambient air that contained them. Optionally, the airintake system may be designed to provide laminar flow in the particlecapture region. Furthermore, in alternate embodiments, theadhesive-coated tape may be replaced with tape not having an adhesivecoating, as Van der Waals forces become proportionally larger asparticle sizes become smaller, may be sufficient to fix particles ofinterest to the tape during transport from the particle capture regionto the particle inspection region. In yet further embodiments, particlesmay first be captured on tape without adhesive, then transferred toadhesive coated tape, in a way that concentrates the density per unitarea of captures particles. Furthermore, in alternate embodiments,particle-capture tape is not used and instead particles are captures onslides or disks that are optionally coated with adhesive.

In a specific embodiment, a pollen or digital optical imaging systemincludes an image sensor, a lens assembly and an illumination source.FIG. 50 shows an example of a pollen imaging system 5000. Pollen grains5005 may be on the surface of a slide 5010 and illuminated 5011A-B by alight sources 5015A-B from above the slide, below the slide, or both. Alens or lens assembly 5020 images 5022 the pollen grains on an imagesensor 5025. The thick black horizontal line segments 5030 represent aniris defining the aperture of the lens assembly.

In a specific embodiment, the image sensors that can be used have beendeveloped and are mass-produced for digital cameras including digitalcameras built into smart phones. These silicon chip devices providemega-pixel RGB images at relatively low cost. A representative pixelpitch for such sensor chips is 1.4 microns. These powerful and low-costimage sensors can be used for the purpose of enabling low-cost automatedpollen monitoring systems.

Because pollen grains are typically only tens of microns in diameter, ina specific embodiment, it is generally preferable for the imaging systemto provide some magnification between the sampled pollen and its imageat the imaging sensor. For example, to provide a factor of fourmagnification, the distance from the lens assembly to the image sensorfor the image sensor may be about four times the distance from the lensassembly to the sampled pollen. As image resolution approaching thewavelength of light is desired, diffraction limited optics withrelatively large apertures may be needed. This makes the problem ofchromatic aberrations more difficult.

Referring to FIG. 50, in a specific embodiment, a pollen imaging systemincorporates quantum dots into the light sources schematicallyrepresented by circles 5015A-B. In one approach, a film containingquantum dots is placed between the pollen sample and a light source suchas an LED, thus sharpening the spectral peaks relative to the originallight source. In another approach, the quantum dots are electricallyexcited to directly create light with desired spectral properties; forexample, quantum dots may be the light emitting elements within an LED.

FIG. 51 shows a block diagram of mobile device 135 according to anotherspecific embodiment. In this specific embodiment, the mobile deviceincludes a wearable computer 5105. In the example shown in FIG. 51, thewearable computer includes a strap 5110 having a fastening mechanismsuch as a buckle or Velcro. The wearable computer can be strapped to theuser's wrist or chest. The wearable computer can include hardware andsoftware similar to that shown in FIG. 7 and described in the discussionaccompanying FIG. 7. For example, the wearable computer may include adisplay 5110, apps including a particle identification app 5115 with anallergic reaction detection subsystem, processor, memory, and one ormore sensors (e.g., microphone, accelerometer, or gyroscope). Thewearable computer may be implemented as a smartwatch. The wearablecomputer may be implemented as a wearable tracking or monitoring devicethat may or may not include a display. One of ordinary skill in the artwould recognize other variations, modifications, and alternatives.

FIG. 52 shows an example of a kit 5252 including a set of replaceableparticle collection cartridges 5253. In the example shown in FIG. 52,the kit includes a box and a tray inside the box. The tray holdsparticle collection cartridge A, particle collection cartridge B, aninstruction manual 5256, and a mailing envelope 2757.

The kit may or may not include the particle collection device. Theinstruction manual provides instructions for inserting a cartridge intoparticle monitor device 150 according to one embodiment, removing thecartridge from the particle monitor device, and (if desired) mailing aused cartridge to a laboratory for further analysis of the particlesthat may have been trapped. The mailing envelope can be a pre-paid andpre-addressed mailing envelop that the user can use to mail thecartridge. In an embodiment, the user purchases a particle monitordevice and can separately purchase additional blank or empty collectioncartridges as desired. In the example shown in FIG. 52, two collectioncartridges are shown. It should be appreciated, however, that a kit mayinclude any number of cartridges such as one, two, three, four, five, ormore than five cartridges.

FIG. 53 is a simplified block diagram of a distributed computer network5300 that may be used in a specific embodiment of a system for airborneparticle collection, detection and recognition. Computer network 5300includes a number of client systems 5313, 5316, and 5319, and a serversystem 5322 coupled to a communication network 5324 via a plurality ofcommunication links 5328. There may be any number of clients and serversin a system. Communication network 5324 provides a mechanism forallowing the various components of distributed network 5300 tocommunicate and exchange information with each other.

Communication network 5324 may itself be comprised of manyinterconnected computer systems and communication links. Communicationlinks 5328 may be hardwire links, optical links, satellite or otherwireless communications links, wave propagation links, or any othermechanisms for communication of information. Various communicationprotocols may be used to facilitate communication between the varioussystems shown in FIG. 53. These communication protocols may includeTCP/IP, HTTP protocols, wireless application protocol (WAP),vendor-specific protocols, customized protocols, and others. While inone embodiment, communication network 5324 is the Internet, in otherembodiments, communication network 5324 may be any suitablecommunication network including a local area network (LAN), a wide areanetwork (WAN), a wireless network, an intranet, a private network, apublic network, a switched network, and combinations of these, and thelike.

Distributed computer network 5300 in FIG. 53 is merely illustrative ofan embodiment and is not intended to limit the scope of the embodimentas recited in the claims. One of ordinary skill in the art wouldrecognize other variations, modifications, and alternatives. Forexample, more than one server system 5322 may be connected tocommunication network 5324. As another example, a number of clientsystems 5313, 5316, and 5319 may be coupled to communication network5324 via an access provider (not shown) or via some other server system.

Client systems 5313, 5316, and 5319 enable users to access and queryinformation stored by server system 5322. In a specific embodiment, a“Web browser” application executing on a client system enables users toselect, access, retrieve, or query information stored by server system5322. Examples of web browsers include the Internet Explorer® and Edge®browser programs provided by Microsoft® Corporation, Chrome® browserprovided by Google®, and the Firefox® browser provided by Mozilla®Foundation, and others. In another specific embodiment, an iOS App or anAndroid® App on a client tablet enables users to select, access,retrieve, or query information stored by server system 5322. Access tothe system can be through a mobile application program or app that isseparate from a browser.

A computer-implemented or computer-executable version of the system maybe embodied using, stored on, or associated with computer-readablemedium or non-transitory computer-readable medium. A computer-readablemedium may include any medium that participates in providinginstructions to one or more processors for execution. Such a medium maytake many forms including, but not limited to, nonvolatile, volatile,and transmission media. Nonvolatile media includes, for example, flashmemory, or optical or magnetic disks. Volatile media includes static ordynamic memory, such as cache memory or RAM. Transmission media includescoaxial cables, copper wire, fiber optic lines, and wires arranged in abus. Transmission media can also take the form of electromagnetic, radiofrequency, acoustic, or light waves, such as those generated duringradio wave and infrared data communications.

For example, a binary, machine-executable version, of the software ofthe present system may be stored or reside in RAM or cache memory, or ona mass storage device. The source, executable code, or both of thesoftware may also be stored or reside on a mass storage device (e.g.,hard disk, magnetic disk, tape, or CD-ROM). As a further example, codemay be transmitted via wires, radio waves, or through a network such asthe Internet.

A client computer can be a smartphone, smartwatch, tablet computer,laptop, wearable device or computer (e.g., Google Glass), body-bornecomputer, or desktop.

FIG. 54 shows a system block diagram of computer system 5401. Computersystem 5401 includes monitor 5403, input device (e.g., keyboard,microphone, or camera) 5409, and mass storage devices 5417. Computersystem 5401 further includes subsystems such as central processor 5402,system memory 5404, input/output (I/O) controller 5406, display adapter5408, serial or universal serial bus (USB) port 5412, network interface5418, and speaker 5420. In an embodiment, a computer system includesadditional or fewer subsystems. For example, a computer system couldinclude more than one processor 5402 (i.e., a multiprocessor system) ora system may include a cache memory.

Arrows such as 5422 represent the system bus architecture of computersystem 5401. However, these arrows are illustrative of anyinterconnection scheme serving to link the subsystems. For example,speaker 5420 could be connected to the other subsystems through a portor have an internal direct connection to central processor 5402. Theprocessor may include multiple processors or a multicore processor,which may permit parallel processing of information. Computer system5401 shown in FIG. 54 is but an example of a suitable computer system.Other configurations of subsystems suitable for use will be readilyapparent to one of ordinary skill in the art.

Computer software products may be written in any of various suitableprogramming languages, such as C, C++, C #, Pascal, Fortran, Perl,Matlab® (from MathWorks), SAS, SPSS, JavaScript®, AJAX, Java®, SQL, andXQuery (a query language that is designed to process data from XML filesor any data source that can be viewed as XML, HTML, or both). Thecomputer software product may be an independent application with datainput and data display modules. Alternatively, the computer softwareproducts may be classes that may be instantiated as distributed objects.The computer software products may also be component software such asJava Beans® (from Oracle Corporation) or Enterprise Java Beans® (EJBfrom Oracle Corporation). In a specific embodiment, a computer programproduct is provided that stores instructions such as computer code toprogram a computer to perform any of the processes or techniquesdescribed.

An operating system for the system may be iOS by Apple®, Inc., Androidby Google®, one of the Microsoft Windows® family of operating systems(e.g., Windows NT®, Windows 2000®, Windows XP®, Windows XP® x64 Edition,Windows Vista®, Windows 7®, Windows CE®, Windows Mobile®, Windows 8,Windows 10), Linux, HP-UX, UNIX, Sun OS®, Solaris®, Mac OS X®, AlphaOS®, AIX, IRIX32, or IRIX64. Other operating systems may be used.Microsoft Windows® is a trademark of Microsoft® Corporation.

Furthermore, the computer may be connected to a network and mayinterface to other computers using this network. The network may be anintranet, internet, or the Internet, among others. The network may be awired network (e.g., using copper), telephone network, packet network,an optical network (e.g., using optical fiber), or a wireless network,or any combination of these. For example, data and other information maybe passed between the computer and components (or steps) of the systemusing a wireless network using a protocol such as Wi-Fi (IEEE standards802.11, 802.11a, 802.11b, 802.11e, 802.11g, 802.11i, and 802.11n, justto name a few examples). For example, signals from a computer may betransferred, at least in part, wirelessly to components or othercomputers.

In an embodiment, with a Web browser executing on a computer workstationsystem, a user accesses a system on the World Wide Web (WWW) through anetwork such as the Internet. The Web browser is used to download webpages or other content in various formats including HTML, XML, text,PDF, and postscript, and may be used to upload information to otherparts of the system. The Web browser may use uniform resourceidentifiers (URLs) to identify resources on the Web and hypertexttransfer protocol (HTTP) in transferring files on the Web.

In the discussion above, for simplicity of presentation, the allergen orparticulate is often referred to as “pollen.” It should be appreciated,however, that the above-described methods are not limited to thedetection and characterization of pollen. Aspects and principles of thesystem can be applied to detecting and identifying any type ofparticulate including allergenic particulates, non-allergenicparticulates, or both. Aspects and principles of the system can beapplied to a microscopic particle imaging system. Aspects and principlesof the system can be applied to an allergen detection system that may ormay not rely on a camera-sensor based imaging system.

A specific application of the system is the monitoring of allergens.Aspects and principles of the system, however, may be applied to otherfields including the study of pollen, i.e., palynology. The collectionand analysis of pollen plays an important role in a number of scientificand applied fields including agriculture and ecology including climatechange effects on seasonal timing and geographical distribution ofairborne pollens. Previous approaches to capturing and analyzingairborne pollen often involved a great deal of manual work and expensiveand bulky equipment. The system including the pollen collection devicesdescribed herein, however, provides an automated, compact, andcost-effective approach to collecting and analyzing pollen.

It should be appreciated that while some embodiments described abovediscuss allergic reactions to pollen, one of skill in the art willrecognize that aspects and principles of the system may be applied toother airborne allergens as well as airborne pathogens of interest toagricultural applications. A specific application of the system is forthe identification or discrimination of airborne particles. It should beappreciated, however, that aspects and principles of the system may beapplied to non-airborne particles.

It should also be appreciated that for embodiments using illuminationsources based on quantum dots, there are corresponding embodiments withalternate illumination sources not based on quantum dots. In many casesquantum-dot based embodiments will be most or very cost-effective, butthis is not necessarily the case for all scenarios. For example, thefluorescent quantum dots of the embodiments illustrated by FIGS. 18, 23and 26 may substituted by other fluorescent materials that are notquantum dots. The LEDs with electronically excited quantum dots of FIGS.24 and 25 may in alternate embodiments be replaced with LEDs usinglight-emitting semi-conductor materials with band gaps tune via othermeans such as composition, or be replaced with tunable laser sources, orbroad spectrum light sources followed by color filters. The airbornebiological particle monitor engineer may utilize quantum dots to theextent that their use reduces the cost or enhances the performance ofthe device.

In a specific embodiment, aspects and principles of the system may beapplied to monitoring a vineyard for agriculture diseases oragricultural pathogens. In this specific embodiment, the collectioncartridge can be hand-held by a user for a manual collection ofparticles that may have collected on a surface of a leaf or grape of agrape vine. In this specific embodiment, a method may include holding acollection cartridge, the collection cartridge comprising an adhesivecoated tape and a slot through which a portion of the tape is exposed;positioning the slot to face an object; pressing the cartridge againstthe object to bring the portion of the tape into contact with a surfaceof the object, thereby transferring particles on the surface to thetape; and inserting the cartridge into a particle monitor for ananalysis of the particles. The object may include a leaf, such as agrape leaf, or a grape such as from a grape vine. The types of particlesof interest to identify may include small pests, insects, bacterium,mildew, mold spores, or combinations of these.

Examples of airborne mildews of interest to vineyards may include Eutypalata, Botrytis, and Cladospora mold among others. Detection of such moldmay be transmitted to a mobile app on the vineyard owner's mobiledevice. The system can provide counts, trends, and predictive data andanalytics displayed via a web application or mobile application. Theapplication allows for customizing alerts for efficient vineyardmanagement operation. The system can provide up-to-the minuteinformation on invasive, disease causing molds, pollens, and weeds.Winds, for example, can carry disease spores for miles. It is desirableto distinguish between harmful and benign molds for successful fungicideoperations. The system allows for 24/7 monitoring and is much morecost-effective than microscopic inspection and visual spot checks. Earlydisease detection and control can increase yield and product quality.

In an embodiment, systems and techniques are provided for the detectionand classification of airborne particles (e.g., pollens, molds, dander,heavy smoke (ash) particles, sand/silica, asbestos, and many others).Systems and techniques are provided for detecting and counting particleshaving a size (e.g., a longest dimension) from about 1 um to about 1500um. In an embodiment, a minimum particle resolution is about 0.3 um. Inanother embodiment, a minimum particle resolution is about 0.1 um). Inan embodiment, a light-based methodology includes five differentmeasurement techniques including deep neural network machine learningand advanced algorithms to extract unique particle signatures leading toclassification. A media cartridge is provided that captures particlesfor physical record archiving, future studies, advanced studies in alaboratory, or combinations of these. An analysis may include particlefeature extraction, vector extraction, executing a classifier algorithm,particle classifications, and aggregating the information into a resultsfile, or combinations of these. The results file may be transmitted to auser's mobile device for display. Particle detection techniques mayinclude morphology (e.g., shape and size), UV fluorescence (e.g., NADH &NAD excitation), colorimetry (e.g., color parameters), topography (e.g.,height and texture), internal structure, or combinations of these.

In a specific embodiment, a method for a tiered-analysis of a particledetected at a pollen monitor includes analyzing the particle at theairborne biological particle monitor to obtain a work-in-progressclassification of the particle, after the analyzing to obtain thework-in-progress classification, transmitting information about theparticle across a network to a server, remote from the pollen monitor,for further analysis, receiving a request from the server for additionalinformation about the particle, and transmitting the additionalinformation from the pollen monitor to the server to allow a finalclassification of the particle.

In another specific embodiment, a method includes receiving at a serverfrom a pollen monitor a request to classify a particle detected at thepollen monitor, requesting additional information from the pollenmonitor, receiving the additional information, determining that theadditional information is insufficient to make a final classification ofthe particle, based on the determination, requesting a manual review ofinformation associated with the particle, receiving the finalclassification of the particle, and upon the receiving the finalclassification of the particle, generating an alert.

In another specific embodiment, a particle monitor does not includequantum dots. In this specific embodiment, an airborne biologicalparticle monitoring device that collects particles floating in airincludes a processor, a camera sensor configured to be controlled by theprocessor, an illumination source configured to be controlled by theprocessor, and logic, where the camera sensor captures an image of theparticles when the collected particles are illuminated by theillumination source, and where the processor processes the logic toanalyze the image to identify the collected particles.

In another specific embodiment, there is an apparatus for monitoringairborne particulates such as allergens, molds, etc. said apparatuscomprising: a means for drawing in ambient air to be monitored; a mediumonto which particulate matter from the air is deposited and held; acomputer or other processing system; one or more illumination systemsfor illumination the medium onto which the particles are deposited; oneor more optical systems for relaying an image of the particles on themedium to an image sensor; software or firmware in the processor tocapture images from the image sensor and analyze the particle images; ameans for exposing areas of the medium for a controlled period of timeand for putting known areas of the medium in the field(s)-of-view of theoptical system(s); and a means for communicating the results of theanalyses to other computing systems for presentation or furtheranalysis.

In the description above and throughout, numerous specific details areset forth in order to provide a thorough understanding of an embodimentof this disclosure. It will be evident, however, to one of ordinaryskill in the art, that an embodiment may be practiced without thesespecific details. In other instances, well-known structures and devicesare shown in block diagram form to facilitate explanation. Thedescription of the preferred embodiments is not intended to limit thescope of the claims appended hereto. Further, in the methods disclosedherein, various steps are disclosed illustrating some of the functionsof an embodiment. These steps are merely examples, and are not meant tobe limiting in any way. Other steps and functions may be contemplatedwithout departing from this disclosure or the scope of an embodiment.Other embodiments include systems and non-volatile media products thatexecute, embody or store processes that implement the methods describedabove.

What is claimed is:
 1. An airborne particle collection systemcomprising: a monitoring device comprising: a housing comprising anair-intake slot, the air-intake slot having a length and a width,wherein the length is greater than the width; a motor; and a camerasensor including a lens; and a removable collection cartridgecomprising: a cartridge housing, separate from the housing of themonitoring device; an adhesive-coated tape contained within thecartridge housing; a supply reel; an uptake reel; and a tape guidecomprising a first segment, and a second segment, wherein the firstsegment defines a particle intake zone, proximate to the air-intake slotwhen the removable collection cartridge has been inserted into thehousing of the monitoring device, and through which the adhesive-coatedtape is exposed to capture airborne particles passing through theair-intake slot, wherein the second segment defines an inspection zoneat which the airborne particles captured at the particle intake zone aretransported for optical imaging, wherein the motor moves the airborneparticles captured by the adhesive-coated tape from the particle intakezone to the inspection zone, and wherein the first and second segmentsare at an angle to each other and the adhesive-coated tape extends fromthe supply reel, across the first and second segments of the tape guide,and to the uptake reel.
 2. The airborne particle collection system ofclaim 1 wherein the monitoring device comprises: a processor; and apower source, wherein the processor processes information and, based onthe processing, directs the motor to move the adhesive-coated tape. 3.The airborne particle collection system of claim 2 wherein themonitoring device comprises: a network interface controller, coupled tothe processor, that receives a plurality of instructions from a remoteserver over a network, wherein the plurality of instructions comprise: afirst instruction to move the collection media; and a second instructionto transmit to the remote server an image of the airborne particles thathave been captured on the collection media.
 4. The airborne particlecollection system of claim 1 wherein the monitoring device is powered byan AC power source.
 5. The airborne particle collection system of claim1 comprising: a light emitting diode (LED) illumination source; anultra-violet (UV) LED illumination source; and an imaging processingmodule, each of the camera sensor, variable lens, LED illuminationsource, UV LED illumination source, and imaging processing module beingcontained within the housing of the monitoring device, and wherein theLED and UV LED illumination sources illuminate the airborne particlescollected onto the collection media for imaging by the camera sensor,the variable lens comprises a lens with an electronically controlledfocal length, and the imaging processing module comprises logic torecognize particles of interest imaged by the camera sensor.
 6. Theairborne particle collection system of claim 1 comprising: a lightemitting diode (LED) illumination source; an ultra-violet (UV) LEDillumination source; and an imaging processing module, each of thecamera sensor, variable lens, LED illumination source, and UV LEDillumination source being contained within the housing of the monitoringdevice, wherein the imaging processing module is at a cloud server,remote from the monitoring device, and wherein the LED and UV LEDillumination sources illuminate the airborne particles collected ontothe collection media for imaging by the camera sensor, the variable lenscomprises a lens with an electronically controlled focal length, and theimaging processing module comprises logic to recognize particles ofinterest imaged by the camera sensor.
 7. The airborne particlecollection system of claim 1 wherein the monitoring device comprises aprocessor, wherein the processor receives information from a remoteserver.
 8. The airborne particle collection system of claim 5 whereinthe camera sensor comprises a red-green-blue (RGB) camera sensor.
 9. Theairborne particle collection system of claim 1 wherein the monitoringdevice comprises a processor identifying a collected particle as beingof a particular type of pollen by transmitting to a remote server ageographical location of the monitoring device, and obtaining from theremote server context information based on the geographical location ofthe monitoring device.
 10. The airborne particle collection system ofclaim 9 wherein the context information comprises at least one of pollentypes known to be currently blooming at the geographical location, windpatterns at the geographical location, or a listing of pollen typesdetected by other monitoring devices.
 11. The airborne particlecollection system of claim 1 comprising a processor identifying acollected particle as being of a particular type of spore bytransmitting to a remote server a geographical location of monitoringdevice, and obtaining from the remote server context information basedon the geographical location of the monitoring device.
 12. The airborneparticle collection system of claim 1 comprising a processor identifyinga collected particle as being of a particular type of biologicalparticle by transmitting to a remote server a geographical location ofthe monitoring device, and obtaining from the remote server contextinformation based on the geographical location of the monitoring device.13. The airborne particle collection system of claim 1 wherein theair-intake slot of the housing aligns with the particle intake zone. 14.The airborne particle collection system of claim 1 wherein theair-intake slot of the housing faces the particle intake zone.
 15. Theairborne particle collection system of claim 1 wherein the first andsecond segments of the tape guide are orthogonal to each other.
 16. Theairborne particle collection system of claim 15 wherein the tape guidecomprises a third segment, the third segment extending between an end ofthe first segment and an end of the second segment.
 17. The airborneparticle collection system of claim 1 wherein airflow in the particleintake zone is turbulent.
 18. The airborne particle collection system ofclaim 5 wherein the LED illumination source comprises quantum-dots. 19.An airborne particle collection system comprising: a monitoring devicecomprising: a housing comprising an air-intake slot, the air-intake slothaving a length and a width, wherein the length is greater than thewidth, and the width varies in a funnel-like fashion from a first valueto a second value, less than the first value, through a thickness of thehousing; a motor; a camera sensor; one or more illumination sources toidentify airborne particles based on optical image characteristics, theone or more illumination sources comprising at least one illuminationsource emitting visible light; and a base; and a removable collectioncartridge comprising: a cartridge housing separate from the housing ofthe monitoring device; an adhesive-coated tape contained within thecartridge housing; and a tape guide comprising a first segment defininga particle intake zone, and a second segment defining an inspectionzone, the first and second segments being orthogonal to each other,wherein the adhesive-coated tape extends across the first and secondsegments of the tape guide, and the first and second segments of thetape guide are at an angle to each other, and wherein the removablecollection cartridge when inserted into the monitoring device, thecamera sensor, and the one or more illumination sources, are positionedsuch that the camera sensor and the one or more illumination sources areabove the removable collection cartridge, the camera sensor and the oneor more illumination sources thereby being further from the base thanthe removable collection cartridge.
 20. An airborne particle collectionsystem comprising: a monitoring device comprising: a housing comprisingan air-intake slot; a motor; a camera sensor; one or more illuminationsources to identify airborne particles based on optical imagecharacteristics; and a base; and a removable collection cartridgecomprising: a cartridge housing separate from the housing of themonitoring device; an adhesive-coated tape contained within thecartridge housing; and a tape guide comprising a first segment defininga particle intake zone, and a second segment defining an inspectionzone, wherein the adhesive-coated tape extends across the first andsecond segments of the tape guide, and the first and second segments ofthe tape guide are orthogonal to each other, wherein the removablecollection cartridge when inserted into the monitoring device, thecamera sensor, and the one or more illumination sources, are positionedsuch that the camera sensor and the one or more illumination sources areabove the removable collection cartridge, the camera sensor and the oneor more illumination sources thereby being further from the base thanthe removable collection cartridge, and wherein the air-intake slotfaces the particle intake zone and comprises a length, and a width,wherein the length is greater than the width, and the width varies in afunnel-like fashion from a first value to a second value, less than thefirst value, through a thickness of the housing to provide airflow inthe particle intake zone that is turbulent.